Up until ~2 weeks I was using Debian 12 with kde 5 and due to some issues I had to reinstall the os. Because of that I decided to instead install kde neon to get access to kde 6 until debian 13 releases. I also installed debian 12 with default shipped gnome on another partition to test it out, which is currently what I use without graphical issues. However when installing kde neon, I first faced issues because the screen way only displaying a flickering single color, which went away after enabling safe graphics. Post installation I managed to log in and everything seemed fine, until I disabled safe graphics and rebooted. When logging in using wayland the flickering color appears right after logging in. Instead I tried to log in using X11 which actually worked at first, until I went into the settings and changed to refresh rate from 60 to 144hz. Since pressing apply it now has the same issue.
System:
cpu: Intel Core i7-9700K
gpu: Nvidia rtx 2080 super
motherboard: ASRock Z390 Pro4
ssd: Intel 512GB 660P NVMe M.2
os: kde neon (latest user edition)
Hi! That seems like a graphics driver issue, just at first glance - are you using the NVIDIA proprietary drivers, or the Nouveau drivers? If the NVIDIA drivers, how were they installed?
Open up the graphical tool that should be now in your menu under settings. Click the additional drivers tab. You should see the drivers for Nvidia. The latest supported driver for the 2xxx series is 550. Click on it, and click update. Reboot when it is done.
Turns out I was still using the nouveau drivers. I had assumed that ubuntu/kde neon came with the proprietary nvidia drivers pre-installed as opposed to debian and never bothered to check ^^'.Now the system is in a mostly usable state except for some minor/medium graphical issues overall and some severe ui problems in certain applications, for which I will do some testing before submitting a bug report on those. But thanks!