Bug 511654

VIDEO (hosted on Reddit): https://www.reddit.com/r/kde/comments/1oon020/comment/nn59yt3/?context=3

SUMMARY
The video explains it all. After moving a window for the third time or more, these rendering artifacts show up and messes up with the transparency and blur of both the window decorations and the background transparency, so I opened up Konsole just to show how notorious this effect is.

In Konsole, the whole window looks messed up as you can see. In other Qt programs it is just the semitransparent backgrounds and the window decorations all go flashy as well.

These glitches are completely invisible through screen recording. I tried to record through OBS to show up the bug but in the recordings these glitches somehow don't show up and the blur appears consistent there, thus why I recorded it with my phone.

It used to appear in 6.3/6.4 and they fixed it but it started happening again.

STEPS TO REPRODUCE
1. Move the window a bit, release mouse, and move again multiple times until it starts flashing on keypress like the video

OBSERVED RESULT
Transparency and blur flashes visible on screen but not on recordings.

EXPECTED RESULT
Completely smooth and non-disappearing blur.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: Arch Linux
KDE Plasma Version: 6.5.1
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0

ADDITIONAL INFORMATION