If you didn’t drag the watch crew in berthing slots (in this case they will not go back themselves on bridge when surfaced) they HAVE to stand back automatically on bridge...if not (I’ve never seen this in SH4) you might have an issue on your side.
Meaning leaving them on bridge when you dive, they disappear underwater like if they were inside, and re-appears automatically when surface.
But best when destroyers around, is to drag and drop them in berthing crew slots to be protected by hull! Otherwise they won’t and can be easily hurt by depth charges...
That’s an SH4 trouble, that’s why modders made those free inside slots available
