I have the same problem - every time I use this mod, the next time I start it up, Hitler has been replaced with Bismarck and the Nazi flag has been replaced with the normal German flag. I've tried everything I can think of - validating files, deleting the cache, removing, resubscribing and reinstalling probably a thousand times - and it seems to be totally random what fixes it. Usually I have to reinstall the mod about a dozen times before the issue suddenly fixes itself, and then only for a single playsession - Bismarck and the normal German flag are back the next time I use it.
I'm totally stumped and it seems silly, but this issue is making it difficult for me to enjoy what I think is a really great mod. Any other possible fixes to this problem?