The game plays fine, but every time I exit, it freezes Windows (11) for some minutes until I get the not responding error message and the option to close it.

goto your bg1 documents and check the actual address is NOT in a sync folder [see image]

I have noticed this just recently as well. I went back to do a new play through because of BG3 and while never having a problem before it now hangs on exit. In my case it was fixed by using the alternate renderer but if I use OpenGL it hangs. I do have my docs in a sync folder but I always had that in the past too so if that is the cause something must have changed on GOG's end I guess.

nothing changed at Gog end its Windows 11 that changed

Fair enough. Either way there was a change and for me at least using the other renderer fixed the issue so it likely will for others.

I've run into the same issue as reported above, with Windows 11 the original Baldur's Gate 1 and 2 run into issues with freezing a great deal.

I tried different setting and found no joy. I originally tried setting the affinity to the core 0 and still the game froze.

When I tried core 1 then it stopped freezing. I'll have to do more experiments but that seems to have fixed the issue.

I spoke to soon, I had another freeze, every time I get into a fight it is freezing. Let me try a few other things.