Thanks for your care. I was not very specific as these troubles have been here for years on different versions.
What version of Ubuntu? You say 22 but there's 22.04 and 22.10.
Roughly since ubuntu 16; now I'm at 22.04
What GPU?
Various NVidia ones, at present it's a GeForce GT 630 Rev. 2
Are you using the Nvidia proprietary drivers or just Nouveau?
Now the proprietary one.
What version of whichever drivers?
nvidia package v 4.70
Are you running in X or Wayland?
X11
What version of Cura?
I started with something like 3.xx years ago, now at 4.11.
Did you get Cura as a regular package, a Snap, or download the AppImage?
Former times a regular package, now AppImages. Both had the same problem.
Have you tested any other programs that use Qt? A whole bunch of them exist but the easiest way to find one is probably just to run something that comes as part of KDE (which uses Qt natively)
Actually, Freecad often presents a garbled main window after resume as well, but that quickly disappears, controls in Freecad never are affected. Otherwise, CURA is the only one with this problem.
HTH, Wolf