recommend posting to https://gitlab.freedesktop.org/drm/amd/ which is home to the issue tracker for AMD graphics on Linux.
KDE
KDE is an international technology team creating user-friendly free and open source software for desktop and portable computing. KDE’s software runs on GNU/Linux, BSD and other operating systems, including Windows.
Plasma 6 Bugs
If you encounter a bug, proceed to https://bugs.kde.org/, check whether it has been reported.
If it hasn't, report it yourself.
PLEASE THINK CAREFULLY BEFORE POSTING HERE.
Developers do not look for reports on social media, so they will not see it and all it does is clutter up the feed.
There's plenty in there going back to 6 months+ sadly I don't think I can bring as much details as everyone's elses posted issues. It's a waiting game from here on :(
Got the same issue here on Kubuntu with when activating transparent background in Konsole with an AMD GPU (flickering of background between transparent and solid).
It only started happening when I switched to Wayland. X11 does not share the issue.
I managed to fix it in Konsole somehow by switching to another apperance theme in the profiles configuration (you might see there that, for some reason, Breeze is duplicated, which I suspect is what responsible for the flickering).
In my case I was using X11 when I posted this. I get flickering on both X11 and wayland and that's a bit ugh sometimes 🙃🙃