DHCP suddenly client stop working

inxi --full --verbosity=7 --filter --no-host

System:
      Kernel: 5.8.11-1-MANJARO x86_64 bits: 64 compiler: N/A Desktop: Xfce 4.14.2 
      tk: Gtk 3.24.20 info: xfce4-panel, plank wm: Openbox 3.6.1 
      dm: LightDM 1.30.0, LXDM Distro: Manjaro Linux 
    Machine:
      Type: Laptop System: LENOVO product: 20NE0002US v: ThinkPad E495 
      serial: <filter> Chassis: type: 10 serial: <filter> 
      Mobo: LENOVO model: 20NE0002US serial: <filter> UEFI: LENOVO 
      v: R11ET32W (1.12 ) date: 12/23/2019 
    Battery:
      ID-1: BAT0 charge: 39.3 Wh condition: 43.4/45.7 Wh (95%) volts: 12.4/11.1 
      model: SMP 01AV447 type: Li-poly serial: <filter> status: Charging 
      cycles: 24 
    Memory:
      RAM: total: 5.75 GiB used: 3.76 GiB (65.5%) 
      RAM Report: permissions: Unable to run dmidecode. Root privileges required. 
    CPU:
      Topology: Quad Core model: AMD Ryzen 5 3500U with Radeon Vega Mobile Gfx 
      bits: 64 type: MT MCP arch: Zen+ rev: 1 L2 cache: 2048 KiB bogomips: 33552 
      Speed: 1614 MHz min/max: 1400/2100 MHz boost: enabled Core speeds (MHz): 
      1: 1763 2: 1451 3: 1710 4: 2036 5: 1276 6: 1231 7: 1271 8: 1231 
      Flags: 3dnowprefetch abm adx aes aperfmperf apic arat avic avx avx2 bmi1 
      bmi2 bpext clflush clflushopt clzero cmov cmp_legacy constant_tsc cpb cpuid 
      cr8_legacy cx16 cx8 de decodeassists extapic extd_apicid f16c flushbyasid 
      fma fpu fsgsbase fxsr fxsr_opt ht hw_pstate ibpb irperf lahf_lm lbrv lm mca 
      mce misalignsse mmx mmxext monitor movbe msr mtrr mwaitx nonstop_tsc nopl 
      npt nrip_save nx osvw overflow_recov pae pat pausefilter pclmulqdq pdpe1gb 
      perfctr_core perfctr_llc perfctr_nb pfthreshold pge pni popcnt pse pse36 
      rdrand rdseed rdtscp rep_good sep sev sha_ni skinit smap smca sme smep ssbd 
      sse sse2 sse4_1 sse4_2 sse4a ssse3 succor svm svm_lock syscall tce topoext 
      tsc tsc_scale v_vmsave_vmload vgif vmcb_clean vme vmmcall wdt xgetbv1 xsave 
      xsavec xsaveerptr xsaveopt xsaves 
    Graphics:
      Device-1: AMD Picasso vendor: Lenovo ThinkPad E595 driver: amdgpu v: kernel 
      bus ID: 05:00.0 chip ID: 1002:15d8 
      Device-2: Acer SunplusIT Integrated Camera type: USB driver: uvcvideo 
      bus ID: 3-2:3 chip ID: 5986:2113 
      Display: x11 server: X.Org 1.20.9 compositor: picom v: git-2c9e7 
      driver: amdgpu,ati unloaded: modesetting alternate: fbdev,vesa 
      resolution: 2560x1440~60Hz s-dpi: 96 
      OpenGL: renderer: AMD RAVEN (DRM 3.38.0 5.8.11-1-MANJARO LLVM 10.0.1) 
      v: 4.6 Mesa 20.1.8 direct render: Yes 
    Audio:
      Device-1: AMD Raven/Raven2/Fenghuang HDMI/DP Audio 
      vendor: Lenovo ThinkPad E595 driver: snd_hda_intel v: kernel 
      bus ID: 05:00.1 chip ID: 1002:15de 
      Device-2: AMD Raven/Raven2/FireFlight/Renoir Audio Processor 
      vendor: Lenovo ThinkPad E595 driver: snd_rn_pci_acp3x v: kernel 
      bus ID: 05:00.5 chip ID: 1022:15e2 
      Device-3: AMD Family 17h HD Audio vendor: Lenovo ThinkPad E595 
      driver: snd_hda_intel v: kernel bus ID: 05:00.6 chip ID: 1022:15e3 
      Sound Server: ALSA v: k5.8.11-1-MANJARO 
    Network:
      Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
      vendor: Lenovo ThinkPad E595 driver: r8169 v: kernel port: 2000 
      bus ID: 02:00.0 chip ID: 10ec:8168 
      IF: enp2s0 state: down mac: <filter> 
      Device-2: Intel Wireless-AC 9260 driver: iwlwifi v: kernel port: 2000 
      bus ID: 04:00.0 chip ID: 8086:2526 
      IF: wlp4s0 state: up mac: <filter> 
      IP v4: <filter> type: dynamic noprefixroute scope: global 
      broadcast: <filter> 
      IP v6: <filter> type: noprefixroute scope: link 
      Device-3: Intel Wireless-AC 9260 Bluetooth Adapter type: USB driver: btusb 
      bus ID: 3-1:2 chip ID: 8087:0025 
      WAN IP: No WAN IP found. Connected to web? SSL issues? Try --no-dig 
    Drives:
      Local Storage: total: 238.47 GiB used: 87.37 GiB (36.6%) 
      ID-1: /dev/nvme0n1 model: UMIS RPJTJ256MED1OWX size: 238.47 GiB 
      speed: 15.8 Gb/s lanes: 2 serial: <filter> rev: 1331.1.0 scheme: GPT 
      Message: No Optical or Floppy data was found. 
    RAID:
      Message: No RAID data was found. 
    Partition:
      ID-1: / size: 62.50 GiB used: 32.19 GiB (51.5%) fs: ext4 
      dev: /dev/nvme0n1p8 label: N/A uuid: 345ab08f-72aa-490a-bdd8-cf012b3ce078 
      ID-2: /boot/efi size: 256.0 MiB used: 266 KiB (0.1%) fs: vfat 
      dev: /dev/nvme0n1p5 label: N/A uuid: 115D-756B 
      ID-3: /home size: 62.95 GiB used: 55.17 GiB (87.6%) fs: ext4 
      dev: /dev/nvme0n1p6 label: N/A uuid: b41b5a60-6984-4d8a-8f6a-da0670432fc9 
    Swap:
      ID-1: swap-1 type: partition size: 8.00 GiB used: 14.0 MiB (0.2%) 
      priority: -2 dev: /dev/nvme0n1p7 label: N/A 
      uuid: f636c589-0c06-40af-b397-40b10cb76695 
    Unmounted:
      ID-1: /dev/nvme0n1p1 size: 260.0 MiB fs: vfat label: SYSTEM uuid: 7EB5-BC64 
      ID-2: /dev/nvme0n1p2 size: 16.0 MiB fs: <superuser/root required> 
      label: N/A uuid: N/A 
      ID-3: /dev/nvme0n1p3 size: 100.51 GiB fs: ntfs label: Windows 
      uuid: 08D6B943D6B93234 
      ID-4: /dev/nvme0n1p4 size: 1000.0 MiB fs: ntfs label: WinRE_DRV 
      uuid: E240BA0440B9DF89 
    USB:
      Hub: 1-0:1 info: Full speed (or root) Hub ports: 4 rev: 2.0 speed: 480 Mb/s 
      chip ID: 1d6b:0002 
      Device-1: 1-2:2 info: SteelSeries ApS SteelSeries Rival 100 Gaming Mouse 
      type: HID,Mouse driver: hid-generic,usbhid interfaces: 2 rev: 1.1 
      speed: 12 Mb/s chip ID: 1038:1702 
      Hub: 2-0:1 info: Full speed (or root) Hub ports: 4 rev: 3.1 speed: 10 Gb/s 
      chip ID: 1d6b:0003 
      Hub: 3-0:1 info: Full speed (or root) Hub ports: 2 rev: 2.0 speed: 480 Mb/s 
      chip ID: 1d6b:0002 
      Device-1: 3-1:2 info: Intel Wireless-AC 9260 Bluetooth Adapter 
      type: Bluetooth driver: btusb interfaces: 2 rev: 2.0 speed: 12 Mb/s 
      chip ID: 8087:0025 
      Device-2: 3-2:3 info: Acer SunplusIT Integrated Camera type: Video 
      driver: uvcvideo interfaces: 2 rev: 2.0 speed: 480 Mb/s chip ID: 5986:2113 
      Hub: 4-0:1 info: Full speed (or root) Hub ports: 1 rev: 3.1 speed: 10 Gb/s 
      chip ID: 1d6b:0003 
    Sensors:
      System Temperatures: cpu: 52.9 C mobo: 0.0 C gpu: amdgpu temp: 52 C 
      Fan Speeds (RPM): cpu: 3300 
    Info:
      Processes: 255 Uptime: 1h 19m Init: systemd v: 246 Compilers: gcc: 10.2.0 
      alt: 5 clang: 10.0.1 Packages: pacman: 1449 Shell: Zsh v: 5.8 
      running in: termite inxi: 3.1.05

~ journalctl -u NetworkManager | tail -100 | grep dhcp

Oct 09 12:33:07 bar-pc NetworkManager[688]: <info>  [1602235987.0578] dhcp4 (wlp4s0): option requested_static_routes => '1'
Oct 09 12:33:07 bar-pc NetworkManager[688]: <info>  [1602235987.0578] dhcp4 (wlp4s0): option requested_subnet_mask => '1'
Oct 09 12:33:07 bar-pc NetworkManager[688]: <info>  [1602235987.0578] dhcp4 (wlp4s0): option requested_time_offset => '1'
Oct 09 12:33:07 bar-pc NetworkManager[688]: <info>  [1602235987.0578] dhcp4 (wlp4s0): option requested_wpad       => '1'
Oct 09 12:33:07 bar-pc NetworkManager[688]: <info>  [1602235987.0578] dhcp4 (wlp4s0): option routers              => '10.0.0.138'
Oct 09 12:33:07 bar-pc NetworkManager[688]: <info>  [1602235987.0578] dhcp4 (wlp4s0): option subnet_mask          => '255.255.255.0'
Oct 09 12:33:07 bar-pc NetworkManager[688]: <info>  [1602235987.0578] dhcp4 (wlp4s0): state changed extended -> extended
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.0426] dhcp4 (wlp4s0): canceled DHCP transaction
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.0427] dhcp4 (wlp4s0): state changed extended -> done
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.2658] dhcp4 (wlp4s0): activation: beginning transaction (timeout in 45 seconds)
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4601] dhcp4 (wlp4s0): option dhcp_lease_time      => '3600'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4602] dhcp4 (wlp4s0): option domain_name          => 'Home'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4602] dhcp4 (wlp4s0): option domain_name_servers  => '10.0.0.138'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4603] dhcp4 (wlp4s0): option expiry               => '1602239998'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4603] dhcp4 (wlp4s0): option ip_address           => '10.0.0.12'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4604] dhcp4 (wlp4s0): option requested_broadcast_address => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4604] dhcp4 (wlp4s0): option requested_domain_name => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4604] dhcp4 (wlp4s0): option requested_domain_name_servers => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4604] dhcp4 (wlp4s0): option requested_domain_search => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4604] dhcp4 (wlp4s0): option requested_host_name  => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4605] dhcp4 (wlp4s0): option requested_interface_mtu => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4605] dhcp4 (wlp4s0): option requested_ms_classless_static_routes => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4605] dhcp4 (wlp4s0): option requested_nis_domain => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4605] dhcp4 (wlp4s0): option requested_nis_servers => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4606] dhcp4 (wlp4s0): option requested_ntp_servers => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4606] dhcp4 (wlp4s0): option requested_rfc3442_classless_static_routes => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4606] dhcp4 (wlp4s0): option requested_root_path  => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4606] dhcp4 (wlp4s0): option requested_routers    => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4607] dhcp4 (wlp4s0): option requested_static_routes => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4607] dhcp4 (wlp4s0): option requested_subnet_mask => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4607] dhcp4 (wlp4s0): option requested_time_offset => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4607] dhcp4 (wlp4s0): option requested_wpad       => '1'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4607] dhcp4 (wlp4s0): option routers              => '10.0.0.138'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4608] dhcp4 (wlp4s0): option subnet_mask          => '255.255.255.0'
Oct 09 12:39:58 bar-pc NetworkManager[688]: <info>  [1602236398.4608] dhcp4 (wlp4s0): state changed unknown -> bound
Oct 09 12:40:00 bar-pc NetworkManager[688]: <info>  [1602236400.1547] dhcp6 (wlp4s0): activation: beginning transaction (timeout in 45 seconds)
Oct 09 12:40:45 bar-pc NetworkManager[688]: <warn>  [1602236445.0692] dhcp6 (wlp4s0): request timed out
Oct 09 12:40:45 bar-pc NetworkManager[688]: <info>  [1602236445.0692] dhcp6 (wlp4s0): state changed unknown -> timeout
Oct 09 12:40:45 bar-pc NetworkManager[688]: <info>  [1602236445.0693] dhcp6 (wlp4s0): canceled DHCP transaction
Oct 09 12:40:45 bar-pc NetworkManager[688]: <info>  [1602236445.0693] dhcp6 (wlp4s0): state changed timeout -> done

Example of the problem:

~ ping 8.8.8.8                                                                                                                                                                                        
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=117 time=66.4 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=117 time=51.6 ms
^C
--- 8.8.8.8 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1002ms
rtt min/avg/max/mdev = 51.597/59.021/66.446/7.424 ms
~ ping www.example.com                                                                                                                                                                                
ping: www.example.com: Name or service not known

In the mean time I have to

sudo systemctl restart systemd-resolved && sudo systemctl stop systemd-resolved

every couple of minutes.

Is there any more useful information I can further provide?

What’s in /etc/resolv.conf and what does systemd-resolve --status say when DNS resolution doesn’t work? Does systemd-resolve www.example.com work at all times?

Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
      vendor: Lenovo ThinkPad E595 driver: r8169

suggest you replace r8169 driver with r8168 driver for NIC

Network-8168 and network-8169 works really bad with my computer
Using Manjaro Settings Manager GUI

OR
Network disconnects for a minute after sleep

sudo mhwd --install pci network-r8168

~ systemd-resolve --status

Global
   LLMNR setting: yes                 
MulticastDNS setting: yes                 
  DNSOverTLS setting: no                  
      DNSSEC setting: allow-downgrade     
    DNSSEC supported: yes                 
  Current DNS Server: 10.0.0.138          
         DNS Servers: 10.0.0.138          
    Fallback DNS Servers: 1.1.1.1             
                          9.9.9.10            
                          8.8.8.8             
                          2606:4700:4700::1111
                          2620:fe::10         
                          2001:4860:4860::8888
              DNS Domain: Home                

Link 2 (enp2s0)
      Current Scopes: none           
DefaultRoute setting: no             
       LLMNR setting: yes            
MulticastDNS setting: no             
  DNSOverTLS setting: no             
      DNSSEC setting: allow-downgrade
    DNSSEC supported: yes            

Link 3 (wlp4s0)
      Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6
DefaultRoute setting: yes                      
       LLMNR setting: yes                      
MulticastDNS setting: no                       
  DNSOverTLS setting: no                       
      DNSSEC setting: allow-downgrade          
    DNSSEC supported: yes                      
  Current DNS Server: 10.0.0.138               
         DNS Servers: 10.0.0.138               
          DNS Domain: ~.                       
                      Home                     

~ systemd-resolve www.example.com

ww.example.com: resolve call failed: DNSSEC validation failed: failed-auxiliary

/etc/resolv.conf:

# Generated by NetworkManager
search Home
nameserver 10.0.0.138

When this DNS outage happens, please run

dig example.com
dig example.com @10.0.0.138
dig example.com @1.1.1.1
dig example.com +trace

and see if any of them work.

@pobrn
Sorry for replying this late, this problem doesn’t come so often lately. And thank you.
~ dig example.com

; <<>> DiG 9.16.6 <<>> example.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3264
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: d643c61cf04cd072010000005f889e7db5d6bf8ada5d18e5 (good)
;; QUESTION SECTION:
;example.com.			IN	A

;; ANSWER SECTION:
example.com.		72940	IN	A	93.184.216.34

;; Query time: 16 msec
;; SERVER: 10.0.0.138#53(10.0.0.138)
;; WHEN: Thu Oct 15 22:09:48 IDT 2020
;; MSG SIZE  rcvd: 84

~ dig example.com @10.0.0.138

; <<>> DiG 9.16.6 <<>> example.com @10.0.0.138
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 12472
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: 3a06121d385da7d5010000005f889e817719e4edf6eb18d4 (good)
;; QUESTION SECTION:
;example.com.			IN	A

;; ANSWER SECTION:
example.com.		72936	IN	A	93.184.216.34

;; Query time: 13 msec
;; SERVER: 10.0.0.138#53(10.0.0.138)
;; WHEN: Thu Oct 15 22:09:52 IDT 2020
;; MSG SIZE  rcvd: 84

~ dig example.com @1.1.1.1

; <<>> DiG 9.16.6 <<>> example.com @1.1.1.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36777
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: f1c208e9b39e8a30010000005f889e8555bdd15f62108bb2 (good)
;; QUESTION SECTION:
;example.com.			IN	A

;; ANSWER SECTION:
example.com.		36357	IN	A	93.184.216.34

;; Query time: 16 msec
;; SERVER: 1.1.1.1#53(1.1.1.1)
;; WHEN: Thu Oct 15 22:09:56 IDT 2020
;; MSG SIZE  rcvd: 84

~ dig example.com +trace

;; Warning: Message parser reports malformed message packet.

; <<>> DiG 9.16.6 <<>> example.com +trace
;; global options: +cmd
.			468252	IN	NS	i.root-servers.net.
.			468252	IN	NS	d.root-servers.net.
.			468252	IN	NS	f.root-servers.net.
.			468252	IN	NS	j.root-servers.net.
.			468252	IN	NS	b.root-servers.net.
.			468252	IN	NS	l.root-servers.net.
.			468252	IN	NS	a.root-servers.net.
.			468252	IN	NS	e.root-servers.net.
.			468252	IN	NS	h.root-servers.net.
.			468252	IN	NS	c.root-servers.net.
.			468252	IN	NS	m.root-servers.net.
.			468252	IN	NS	g.root-servers.net.
.			468252	IN	NS	k.root-servers.net.
couldn't get address for 'i.root-servers.net': not found
couldn't get address for 'd.root-servers.net': not found
couldn't get address for 'f.root-servers.net': not found
couldn't get address for 'j.root-servers.net': not found
couldn't get address for 'b.root-servers.net': not found
couldn't get address for 'l.root-servers.net': not found
couldn't get address for 'a.root-servers.net': not found
couldn't get address for 'e.root-servers.net': not found
couldn't get address for 'h.root-servers.net': not found
couldn't get address for 'c.root-servers.net': not found
couldn't get address for 'm.root-servers.net': not found
couldn't get address for 'g.root-servers.net': not found
couldn't get address for 'k.root-servers.net': not found
dig: couldn't get address for 'i.root-servers.net': no more