https://bugzilla.kernel.org/show_bug.cgi?id=199319
--- Comment #5 from mail@rainer-finke.de --- Thanks for the hint with vsync, but it didn't change anything for me on Plasma-Wayland.
At least I noticed, that the bright flickering on my screen on Plasma-Wayland when moving the mouse appears was due to night shift changing the colours. It worked well on Linux 4.15. But on Linux 4.16 I need to deactivate it so that the flickering on Plasma-Wayland during the mouse movements stops.
With night shift and even vsync disabled, there is now just from time to time a flickering, irregularly.