Solved
Alt-tabbing will lead to GPU driver hang
I have no clue why this happens and i'm long past trying to figure out why dx12 game would even react to being alt-tabbed. Nevertheless, the game randomly will stop rendering upon alt-tabbing, if ...
Apparently this may be a freak interaction between nvidia 5000 series cards, nvidia drivers for said series and Windows 11 MPO implementation.
Disabling MPO seems to have resolved this particular issue.
