Does the issue also occur if you switch from a Plasma X11 to a Plasma Wayland session? I noticed that the other user who seems to be experiencing a similar issue has “DE / WM: KDE Plasma / KWin (X11)” in their user profile.
The fact that both of you are using X11 may be just a coincidence, but kwin_x11 was recently split from kwin_wayland. Development work is being focused on kwin_wayland. kwin_x11 is being maintained by a team of volunteers, meaning it will get no new features and will only receive back-ported bug-fixes & security updates.