I hope it's not making much difference that I'm posting my question here even if I'm using Pop!_OS. The problem also occurs on a Manjaro live usb.
I'm using a
- Ryzen 1500x CPU,
- 16GB of RAM,
- MSI B350m Gaming Pro motherboard with an RX 580 8GB version,
- Monitor is AOC G2260VWQ6 1920x1080x75hz.
After booting and logging in everything is fine, however, after turning the screen off and then on, going back from a screensaver, changing display settings that makes the screen "restart" or anything similar while being on a refresh rate over 60hz, which is ~75hz for my screen, the weird flicker starts happening.
Here are links with videos for different situations:
Everything being fine after login: https://streamable.com/am3kp
Screen starts flickering after locking (turns off the screen after a second) and then logging back in: https://streamable.com/meeiz
Fixing the flicker by changing the resolution and reverting: https://streamable.com/5l5z2
Sometimes it still works fine, but it only happened once, restarting the screen multiple times didn't begin the flicker, until reboot.
I tested it using both DisplayPort and HDMI, with higher refresh rates on lower resolutions the problem still occurs. When switching to a different resolution and still using ~75hz the flicker doesn't go away.
It happens on both Mesa version 18 and 19, on Manjaro it still happened on even when switching to kernel version 5. Of course, the problem doesn't occur in Windows.
I'm not that advanced in Linux so I really don't know how to fix it. Please help.
EDIT: After searching a bit more I found a workaround. I had to change "auto" to "high" in file /sys/class/drm/card0/device/power_dpm_force_performance_level. Link to the thread I found the workaround on: https://bbs.archlinux.org/viewtopic.php?id=244398