SUMMARY

Plasma crashes when changing system monitor widgets display style from one of table (Applications Table or Process Table) to any other display style (of table type or not).

STEPS TO REPRODUCE
1. Add a widget to the desktop
2. Enter settings
3. Chose "Appearance" group
4. Set display mode as Applications Table or Process Table
5. Apply
6. The widget behaves as expected
7. Select other display mode  
8. Apply

OBSERVED RESULT

Plasma desktop crashes and gracefully restarts after a black desktop (not black screen, the screen does not seem to go black entirely)

EXPECTED RESULT

The mode changes successfully, without a crash.

SOFTWARE/OS VERSIONS
Operating System: Gentoo Linux
KDE Plasma Version: 5.21.4
KDE Frameworks Version: 5.81.0
Qt Version: 5.15.2
Kernel Version: 5.7.0-sabayon
OS Type: 64-bit
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7 CPU 920 @ 2.67GHz
Memory: 23,5 GiB of RAM
Graphics Processor: GeForce GTX 1060 6GB/PCIe/SSE2

ADDITIONAL INFORMATION

It always crashes this way.
First time it crashed it created a report, but never after. Unfortunately, I've not managed to send the report, when I have pressed to submit, it just closed.