Some VST plugins wont work in new hardware

Newly migrated my ancient Cubase 5 setup from win 10 to win 11 (both 64 bit though).
Cubase 5 itself runs fine but some plugins wont show up even if they are in the right folder:

These work fine:
Antares auto-tune
Addictive drums (XLN audio)

These don’t show up at all
Addictive keys (XLN audio) (wierd since it’s so similar to the drums which work)
GVI (Giga virtual instrument)

Especially the last one (GVI) is very important to me. Veery old yes but i would love for this to work rather than needing to reinstall win 10 again. But is it really windows version that is triggering this problem? Both were 64 bit.

Thanks for any help!