As a workaround, in plasma you can move a window by grabbing anywhere with the mouse if you just hold super
or alt
first - depending on how you have it configured. Same for resizing using the right mouse button. I never rely on borders or title bars for these things.
That does move the window around, but resizing the window with the mouse does not work. So, I can move the window around, but I can’t resize the window so it is between the panel bars.
you need to drag it with the other mouse button to resize it - not working?
Only side to side…I get an arrow in the corner, but the windows will not resize diagonally. Oddly it is the KDE apps (Settings, KDenlive) that don’t work. Vivaldi resizes fine.