After fresh installation of Tumbleweed to a new hardware (Ryzen Threadripper +
AMD gfx) copy and cut with ctrl+c/x started working unreliably (never
experienced this with the previous hardware setups). After KDE is started these
work OK but after few hours already copy and cut start to miss these presses.
2nd press usually works but not always.

After several days without restarting KDE this problem gets more severe -
misses more often. Also, strange behaviour happens with Dolphin for example.
When ctrl+x is pressed the file/folder icon flicks quickly to greyed out (cut
selection) and back to normal. It becomes difficult to press ctrl+x so that cut
selection remains. Holding ctrl+x pressed for repeat the icon start to flicker
between normal and selected.

Tried changing clipboard configuration options but none have made any
difference to the problem.

I have not seen issues with paste i.e. if there's something on a clipboard it
can be pasted.

This is not only ctrl+c/x button combination issue but same applied to
selecting copy&cut from application menus. All applications (KDE basic apps,
LibreOffice, Thunderbird, Firefox..) I use suffer from this problem thus it
seems to be KDE related issue.

This has been an issue for several months (since installation early 2019). In
the beginning it was even worse i.e. some updates have reduced the issue a bit
but not much.