I have this graphical issue of applications flashing all white background, this happens in certain applications like Steam client and Firefox browser, this flashing happens when loading websites or during initialization. sometimes Firefox browser flashes background that is colored the same as its installed theme accent instead of a white background.
Here is a video of the issue:
When using full-screen TTY session to manually start Xserver or Lightdm, it start an Xfce4 desktop environment where some of its settings is different to the of stock Linuxmint and the behavior of the issue changes as :
Firefox browser now consistently flashes background that is colored the same as its installed theme accent instead of a white background
Steam client now flashes with all black background except when its minimized and then maximized again.
This issue occurs in both nvidia 590 driver and the open source nouveau driver from the native repositories , this doesn’t happens when using the integrated intel GPU.
Thanks for the detailed report and logs. Your nvidia-bug-report shows driver 595.71.05 on an RTX 3060 driving a 4480×1440 dual-monitor setup (BenQ HDMI + SKG DisplayPort), and we do not see NVRM/Xid errors associated with the flashes.
Because the flashes occur during application initialization/page load (Firefox, Steam) and you also see similar behavior on nouveau, this looks more like compositor/window repaint behavior than a proprietary driver failure. The Firefox accent-colored flash in particular is consistent with the application clearing its window before the first frame is drawn.
Please try: (1) single-monitor testing, (2) nvidia-settings -a AllowFlipping=0, (3) enabling Force Full Composition Pipeline on both displays, (4) disabling Cinnamon compositor effects, and (5) Firefox with hardware acceleration off. Also please confirm how the “Intel iGPU works” test was done — your bug report shows only the NVIDIA GPU in lspci.
If the issue remains on a clean single-monitor setup after those steps, please reply with a short screen recording and updated nvidia-bug-report.log from that simplified configuration.