Post number 1. So first, welcome to the board
Very possible you still get the banging, even with the generator running, but just may not hear it.
Most coaches have a ATS (Automatic Transfer Switch) that sits around waiting for power to be 'detected'. Once it is, it 'switches' this power into the coaches electrical system. The 'bang' is the ATS electronically switching the switch of power into the coach.
(Now, since this is your first post. Let me assure you, that others that can describe ATS better then I did, will do so... Plus, if they feel this is bad input, good chance they will 'correct' my thoughts, and point you in a better direction. (It's the nature of the board, to very carefully 'correct' Smitty, when he is wrong. It's my way of helping other board members, feel very knowledgeable
All kidding aside, everything could be working by design. Hope it is, and again, welcome to the board!
Travel safe, and have fun,