Only on this PC I have, since last summer, but recently very often, many system (or rather: mouse and keyboard) freezing.
Manly when I click on the x at right top corner of a window, sometimes the system freezes, that is I cannot use mouse and keyboard for a while (20/30 sec.), while music keep playing, and after that time I have only a short time of "normality" followed by another freezing. Until Ia do a complete restart (with magic keys).

I have already reported this problem on https://bugs.kde.org/show_bug.cgi?id=446075 KDE bugs, where you can find some my logs, but so far nobody has answered.

My hardware:
CPU: Quad Core AMD Ryzen 3 3200G with Radeon Vega Graphics (-MCP-) speed/min/max: 1395/1400/3600 MHz
Kernel: 5.11.0-43-generic x86_64 Up: 5h 12m Mem: 2636.9/5861.7 MiB (45.0%) Storage: 1.03 TiB (63.4% used) Procs: 250
Shell: bash 5.0.17 inxi: 3.0.38

My system:
Operating System: KDE neon 5.23
KDE Plasma Version: 5.23.4
KDE Frameworks Version: 5.89.0
Qt Version: 5.15.3
Kernel Version: 5.11.0-43-generic (64-bit)
Graphics Platform: X11
Processors: 4 × AMD Ryzen 3 3200G with Radeon Vega Graphics
Memory: 5,7 GiB of RAM
Graphics Processor: AMD Radeon™ Vega 8 Graphics.

What tests should I do?
Thank you!

Nobody answered because you filed it under an unassigned product which is not for plasmashell issues. I changed the product on that bug report.

When unsure about what product to file a bug report to: If you are using Plasmashell and experience problems with it the plasmashell is the product to file the report to, else ask in this forum with a link to the report.

ok, I got, thank you!