Mine is that the "fake session restore" hasn't landed yet (it will in 6.1) so the half-dozen konsole and dolphin windows I tend to leave open between reboots don't re-open after rebooting under Wayland.
The reason it's called "fake session restore" is that the Wayland session restore protocol isn't finalized, so as a temporary workaround Plasma on Wayland will re-launch the applications and leave it up to the individual programs to restore their last state.
For some reason when i use Wayland it shows weird artifacts on the bottom of my screen. Doesn't happen on X11 so I'll stick with that until it gets fixed
Definitely needs a bug report.
I recommend go into Wayland and use hw-probe and run : sudo -E hw-probe -all -upload -dump-acpi -decode-acpi
And use the given link in your BR.
Try to force the bug, and take a screenshot or if it doesn't show up in the screenshot take a picture with your phone and mention it doesn't show up in screenshots.
If you're able to consistently reproduce the bug include how.
Make the BR to Kwin.
Not really. I was a heavy critic of the state kde was in because of fractional scalling sucking a lot, but I've been using it on 2 pcs and am now pretty happy. Does everything I need it to.