I don't think #Plasma6 is ready for prime time. When I open apps, the title bar goes above the screen space and I can't move or close the app or use the menus.
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.
