I've been getting this flickering issue ever since I got two screens, both are the same resolution and I've set them both to 60Hz in case that was an issue.
Here is a video: https://streamable.com/gzb81i

Every time I put my screen on standby, or put the computer to sleep it will get the flickering again once I wake it, but I never get the problem after a restart.
if I unplug one screen for a couple of seconds and plug it back in, the problem goes away as well.

I have this issue on KDE Neon, ManjaroKDE and Kubuntu but I never had it on Ubuntu gnome or windows and the problem only started happening when I got 2 screens.

I have tried setting Vsync to full-screen repaints and changed the compositor to 2.0 from 3.1 and back again. Not sure what else to try or look for?

I'm hoping someone can give me a hand

What Graphic card? There is at least a problem reported by AMD with the most recent drivers for the 4000 Ryzen series I know of, could well be a similar problem on other drivers/cards.

Thanks for helping out!

It's an RX 5600 XT. How can I confirm if it's the graphics card and/or how would I go about fixing it?

Since this depends on the amdgpu driver you use, there is nothing we can do on our side. It has to be fixed by the manufacturer of the card

Another potential issue can be if you connect your screens with HDMI: this can usually be solved with a high-end HDMI cable (HDMI 2.1 8 k) that is not longer than 1 m. Unfortunately HDMI can be a tricky beast, too.

I'm using Displayport so it wouldn't be an HDMI issue. The driver issue is probably the cause as you say. I guess I'll have to wait and hope that it gets fixed in time.

Thanks for your help.

Hi, I've just encountered this issue in Kubuntu 21.10. I did not have it in Kubuntu 21.04 for at least a year. It's the same machine, so I don't think it is a graphic card issue. Nothing else has changed but the OS. The fact that the OP did not have this issue in ubuntu suggests the same. Any idea what difference between ubuntu and kubuntu would cause this?

ps: I am also using displayport....

I'm also experiencing this issue on latest drivers 6900 XT. I found this issue occurs less often when latency in compositor settings is set to "force lowest latency". Unfortunately in my experience that usually leads to dropping tons of frames though which can make perfectly performing games feel super laggy. I'm not sure if this is an AMD issue or a KDE issue though.