I would imagine there was some screening going on. Ardent, arrogant Nazi SS types probably didn’t get that treatment. The regular Wehrmacht stiffs were OK. And as fso301 pointed out; where were they going to go?
After all, this was the United States of America. They had it better here as POWs than they had it back in Germany. That’s why so many tried to come back.
Excellent points all. I suppose as long as the POWs were on good behavior, avoiding serious incidents of crime or sabotage, they could be permitted some leniency. I imagine that was explained to them, which would encourage self-policing.