Created attachment 154756 [details]
Presentation of this bug under X11

SUMMARY
Windows become blurry and unresponsive if snapping them to a corner with the mouse or keyboard (i.e., Meta + Arrow keys).


STEPS TO REPRODUCE
1. Snap a window into a corner

OBSERVED RESULT
Window is not fully rendered. It is blurry and unresponsive. Even though it continues to work under the hood, the UI is not updated anymore until keystrokes are given and subsequently waiting for about half a second (works for the KSysLog application). Or the window is resized (works for Konsole).

EXPECTED RESULT
UI is normally refreshed without blurs or UI freezes.

SOFTWARE/OS VERSIONS
Operating System: Manjaro Linux
KDE Plasma Version: 5.26.4
KDE Frameworks Version: 5.101.0
Qt Version: 5.15.7
Kernel Version: 6.0.14-1-MANJARO (64-bit)
Graphics Platform: X11
Processors: 12 × AMD Ryzen 5 5600X 6-Core Processor
Memory: 31,3 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 970/PCIe/SSE2
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: B550 AORUS ELITE V2

It appears on my Laptop (other machine) as well.

ADDITIONAL INFORMATION
Whenever the bug appears, a log like this is shown in KSysLog:
kwin_core: precision lost! floating value sent to X .....

It happens under X11 and Wayland. The difference is that under Wayland texts become a bit blurry but I never observed the UI to freeze. Freezing only happens under X11 for me, so it's less severe under Wayland.

More concrecte output under Wayland:

Snapping the KSysLog window to the lower half of the screen:
kwin_wayland	kwin_core: precision lost! floating value sent to X 521.5
kwin_wayland	kwin_core: precision lost! floating value sent to X 521.5
kwin_wayland	kwin_core: precision lost! floating value sent to X 492.5
kwin_wayland	kwin_core: precision lost! floating value sent to X 492.5
kwin_wayland	kwin_core: precision lost! floating value sent to X 550.5
kwin_wayland	kwin_core: precision lost! floating value sent to X 492.5
kwin_wayland	kwin_core: precision lost! floating value sent to X 521.5

Snapping the KSysLog window to the upper half of the screen:
kwin_wayland	kwin_core: precision lost! floating value sent to X 521.5
kwin_wayland	kwin_core: precision lost! floating value sent to X 492.5
kwin_wayland	kwin_core: precision lost! floating value sent to X 492.5
kwin_wayland	kwin_core: precision lost! floating value sent to X 492.5
kwin_wayland	kwin_core: precision lost! floating value sent to X 521.5

The problems disappears overall if I disable compositing.

My screens are ordinary 1920x1080 screens and the Global Scale is set to 100%. I didn't change any settings for the compositor or graphical effects.