Same problem I have with N7.
Closing Nuendo is not an easy task. In best scenario closing the Nuendo with 2 clicks and waiting. In some cases I need to wait more and sometime the sofware if freezing.
This problem is more dominant in N7 but now also with N8.
Just wondering- Are you also using Kontakt? I find Nuendo locks up on closing much more easily/often when I’m using Kontakt (complete 10).
I do have Kontakt. but it doesnt have anything to do with the problem cause Im not using it all the time.