Xfce - Standby problems

Hello forum

no one in the German forum could help me. So here it is again, translated with DeepL.

When Xfce has been on standby, it often does not wake up properly. The screen either shows an error message (wrong resolution, or something like that), is distorted or has stripes. After pressing Alt-Ctrl-F2 and then Alt-F7, everything works again. Also

systemctl restart lightdm

works as a solution.

Sometimes this problem does not occur for days, sometimes it feels like five times a day. It does not matter whether programmes were open or not when the computer was sent to sleep.

The second problem is the automatic shutdown (for example after 15 minutes) in standby. Sometimes it goes well for days, sometimes the problem comes again and again in a row (which makes it so difficult to track).

If the computer goes into standby by itself (!), the internet often doesn’t work anymore, the network icon is grey. I can get rid of this with

systemctl restart NetworkManager.service

but there must be a lot going on in the background, because the computer can’t be switched off properly. The only thing that helps is a reset.

mhwd -i pci network-r8168

has brought nothing.

I only access the Internet with cable. WiFi is switched off.

Swap or no swap did nothing either. I don’t have swap at the moment.

gesamt       benutzt     frei      gemns.  Puffer/Cache verfügbar
Speicher:       31Gi       2,7Gi       265Mi       172Mi        28Gi        27Gi
Swap:             0B          0B          0B

I’ve had both problems for quite a long time, so it probably can’t be the kernel. It has been replaced many times. I also had these problems with Xfce 4.14.

I don’t have these problems with KDE or Cinnamon. Can anyone help?

(desktop computer)

Kernel: 5.15.7-1-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0
    Desktop: Xfce 4.16.0 tk: Gtk 3.24.29 info: xfce4-panel wm: xfwm 4.16.1
    vt: 7 dm: LightDM 1.30.0 Distro: Manjaro Linux base: Arch Linux

  Device-1: NVIDIA GP104 [GeForce GTX 1080] vendor: Hewlett-Packard
    driver: nvidia v: 495.44 bus-ID: 01:00.0 chip-ID: 10de:1b80 class-ID: 0300

Display: x11 server: X.Org compositor: xfwm4 v: 4.16.1 driver:
    loaded: nvidia resolution: 3840x2160~60Hz s-dpi: 159
  Message: Unable to show advanced data. Required tool glxinfo missing.

  Device-1: Intel Wireless 3165 driver: iwlwifi v: kernel bus-ID: 03:00.0
    chip-ID: 8086:3165 class-ID: 0280
  IF: wlp3s0 state: down mac: <filter>
  Device-2: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet
    vendor: Hewlett-Packard driver: r8169 v: kernel port: d000 bus-ID: 04:00.0
    chip-ID: 10ec:8168 class-ID: 0200
  IF: enp4s0 state: up speed: 1000 Mbps duplex: full mac: <filter>