Firefox flickering with latest Manjaro stable update

With the latest Manjaro stable update Firefox started to flickering/had graphical glitches all over. I’m using KDE X11 Session. Any ideas what can be the cause, what I can try or what further information I should provide?

Edit: It seems only to appear when I have Twitch streams open.

Which version of Firefox ?

90.0.1

Can you gives some system info ?

inxi -Fza
on console ?

System:    Kernel: 5.13.1-3-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0 
           parameters: BOOT_IMAGE=/boot/vmlinuz-5.13-x86_64 
           root=UUID=028ed5bf-7a36-406b-b781-10ae62408e41 rw quiet 
           resume=UUID=14640b8a-bd13-4b61-adb4-53a8d09ffdfa udev.log_priority=3 
           Desktop: KDE Plasma 5.22.3 tk: Qt 5.15.2 wm: kwin_x11 vt: 1 dm: SDDM 
           Distro: Manjaro Linux base: Arch Linux 
Machine:   Type: Desktop System: Hewlett-Packard product: HP Z420 Workstation v: N/A 
           serial: <filter> Chassis: type: 6 serial: <filter> 
           Mobo: Hewlett-Packard model: 1589 v: 0.00 serial: <filter> UEFI: Hewlett-Packard 
           v: J61 v03.96 date: 10/29/2019 
CPU:       Info: 6-Core model: Intel Xeon E5-1650 v2 bits: 64 type: MT MCP arch: Ivy Bridge 
           family: 6 model-id: 3E (62) stepping: 4 microcode: 42E cache: L2: 12 MiB 
           flags: avx lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 83820 
           Speed: 3593 MHz min/max: 1200/3900 MHz Core speeds (MHz): 1: 3593 2: 3596 3: 3600 
           4: 3606 5: 3607 6: 3593 7: 3600 8: 3609 9: 3595 10: 3611 11: 3610 12: 3618 
           Vulnerabilities: Type: itlb_multihit status: KVM: VMX disabled 
           Type: l1tf mitigation: PTE Inversion; VMX: conditional cache flushes, SMT vulnerable 
           Type: mds mitigation: Clear CPU buffers; SMT vulnerable 
           Type: meltdown mitigation: PTI 
           Type: spec_store_bypass 
           mitigation: Speculative Store Bypass disabled via prctl and seccomp 
           Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer sanitization 
           Type: spectre_v2 mitigation: Full generic retpoline, IBPB: conditional, IBRS_FW, 
           STIBP: conditional, RSB filling 
           Type: srbds status: Not affected 
           Type: tsx_async_abort status: Not affected 
Graphics:  Device-1: AMD Baffin [Radeon RX 460/560D / Pro 450/455/460/555/555X/560/560X] 
           vendor: XFX Pine driver: amdgpu v: kernel bus-ID: 03:00.0 chip-ID: 1002:67ef 
           class-ID: 0300 
           Device-2: AMD Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] vendor: ASUSTeK 
           driver: amdgpu v: kernel bus-ID: 04:00.0 chip-ID: 1002:67df class-ID: 0300 
           Display: x11 server: X.Org 1.20.11 compositor: kwin_x11 driver: loaded: amdgpu 
           unloaded: modesetting alternate: ati,fbdev,vesa display-ID: :0 screens: 1 
           Screen-1: 0 s-res: 9120x3440 s-dpi: 96 s-size: 2413x910mm (95.0x35.8") 
           s-diag: 2579mm (101.5") 
           Monitor-1: DisplayPort-0 res: 2560x1440 hz: 60 dpi: 123 size: 527x296mm (20.7x11.7") 
           diag: 604mm (23.8") 
           Monitor-2: DisplayPort-1-1 res: 5120x2160 dpi: 163 size: 800x330mm (31.5x13.0") 
           diag: 865mm (34.1") 
           Monitor-3: HDMI-A-1-1 res: 1440x2560 hz: 60 
           Monitor-4: DVI-D-1-2 res: 1920x1080 hz: 60 dpi: 102 size: 477x268mm (18.8x10.6") 
           diag: 547mm (21.5") 
           OpenGL: renderer: AMD Radeon RX 470 Graphics (POLARIS10 DRM 3.41.0 5.13.1-3-MANJARO 
           LLVM 12.0.0) 
           v: 4.6 Mesa 21.1.4 direct render: Yes 
Audio:     Device-1: AMD Baffin HDMI/DP Audio [Radeon RX 550 640SP / RX 560/560X] 
           vendor: XFX Pine driver: snd_hda_intel v: kernel bus-ID: 03:00.1 chip-ID: 1002:aae0 
           class-ID: 0403 
           Device-2: AMD Ellesmere HDMI Audio [Radeon RX 470/480 / 570/580/590] vendor: ASUSTeK 
           driver: snd_hda_intel v: kernel bus-ID: 04:00.1 chip-ID: 1002:aaf0 class-ID: 0403 
           Device-3: Samson Meteor condenser microphone type: USB 
           driver: hid-generic,snd-usb-audio,usbhid bus-ID: 2-1.1.4:7 chip-ID: 17a0:0310 
           class-ID: 0300 
           Sound Server-1: ALSA v: k5.13.1-3-MANJARO running: yes 
           Sound Server-2: JACK v: 0.125.0 running: no 
           Sound Server-3: PulseAudio v: 14.2 running: yes 
           Sound Server-4: PipeWire v: 0.3.31 running: yes 
Network:   Device-1: Intel 82579LM Gigabit Network vendor: Hewlett-Packard driver: e1000e 
           v: kernel port: e040 bus-ID: 00:19.0 chip-ID: 8086:1502 class-ID: 0200 
           IF: eno1 state: up speed: 1000 Mbps duplex: full mac: <filter> 
           Device-2: Realtek RTL8169 PCI Gigabit Ethernet driver: r8169 v: kernel port: a000 
           bus-ID: 06:04.0 chip-ID: 10ec:8169 class-ID: 0200 
           IF: enp6s4 state: up speed: 1000 Mbps duplex: full mac: <filter> 
Bluetooth: Device-1: ASUSTek ASUS USB-BT500 type: USB driver: btusb v: 0.8 bus-ID: 3-4:3 
           chip-ID: 0b05:190e class-ID: e001 serial: <filter> 
           Report: rfkill ID: hci0 rfk-id: 0 state: up address: see --recommends 
Drives:    Local Storage: total: 3.18 TiB used: 1.22 TiB (38.4%) 
           SMART Message: Unable to run smartctl. Root privileges required. 
           ID-1: /dev/sda maj-min: 8:0 vendor: Crucial model: CT500MX500SSD1 size: 465.76 GiB 
           block-size: physical: 4096 B logical: 512 B speed: 6.0 Gb/s rotation: SSD 
           serial: <filter> rev: 023 scheme: GPT 
           ID-2: /dev/sdb maj-min: 8:16 vendor: SanDisk model: SDSSDH3500G size: 465.76 GiB 
           block-size: physical: 512 B logical: 512 B speed: 6.0 Gb/s rotation: SSD 
           serial: <filter> rev: 70RL scheme: GPT 
           ID-3: /dev/sdc maj-min: 8:32 vendor: Kingston model: SA400S37240G size: 223.57 GiB 
           block-size: physical: 512 B logical: 512 B speed: 3.0 Gb/s rotation: SSD 
           serial: <filter> rev: B1D1 scheme: GPT 
           ID-4: /dev/sdd maj-min: 8:48 vendor: Seagate model: ST1000DX001-1CM162 
           size: 931.51 GiB block-size: physical: 4096 B logical: 512 B speed: 3.0 Gb/s 
           rotation: 7200 rpm serial: <filter> rev: CC62 scheme: GPT 
           ID-5: /dev/sde maj-min: 8:64 vendor: Seagate model: ST1000DX001-1CM162 
           size: 931.51 GiB block-size: physical: 4096 B logical: 512 B speed: 3.0 Gb/s 
           rotation: 7200 rpm serial: <filter> rev: CC43 scheme: GPT 
           ID-6: /dev/sdf maj-min: 8:80 vendor: SanDisk model: SDSSDHP256G size: 238.47 GiB 
           block-size: physical: 512 B logical: 512 B speed: <unknown> rotation: SSD 
           serial: <filter> rev: 6RL scheme: GPT 
Partition: ID-1: / raw-size: 238.22 GiB size: 233.48 GiB (98.01%) used: 21.46 GiB (9.2%) fs: ext4 
           dev: /dev/sdf1 maj-min: 8:81 
           ID-2: /boot/efi raw-size: 250 MiB size: 246.1 MiB (98.46%) used: 298 KiB (0.1%) 
           fs: vfat dev: /dev/sdf2 maj-min: 8:82 
           ID-3: /home raw-size: 883.51 GiB size: 868.64 GiB (98.32%) used: 804.41 GiB (92.6%) 
           fs: ext4 dev: /dev/sdd2 maj-min: 8:50 
Swap:      Kernel: swappiness: 60 (default) cache-pressure: 100 (default) 
           ID-1: swap-1 type: partition size: 48 GiB used: 0 KiB (0.0%) priority: -2 
           dev: /dev/sdd1 maj-min: 8:49 
Sensors:   System Temperatures: cpu: 62.0 C mobo: N/A 
           Fan Speeds (RPM): N/A 
           GPU: device: amdgpu temp: 57.0 C fan: 1807 watts: 28.18 device: amdgpu temp: 60.0 C 
           fan: 1840 watts: 35.16 
Info:      Processes: 344 Uptime: 7h 35m wakeups: 0 Memory: 31.29 GiB used: 8.09 GiB (25.9%) 
           Init: systemd v: 248 tool: systemctl Compilers: gcc: 11.1.0 Packages: pacman: 1369 
           lib: 426 Shell: Bash v: 5.1.8 running-in: konsole inxi: 3.3.05

Can you try disabling hardware acceleration?

Doesn’t work.

As I searched for my problem with the key words Firefox and flickering I didn’t find anything helpful. But I search now Firefox glitches and found this thread.

Set gfx.webrender.force-disabled to true in about:config and restart Firefox.

Seems to be working at the moment. But I have to observe a while before I can confirm. The other option mentioned in the link I don’t test yet.

Setting gfx.webrender.force-disabled to true seems to have solved the issue for me, at least for now. We’ll see how long it holds.