OP, I see you in another thread. Is this ONAN power issue resolved? We have the Microlite 4000 (which is gasoline, I suspect your 3600 is that genset but set up for propane) and our genset breaker (inside the sound enclosure as noted above) releases when the coach's main panel or the campground pedestal will not. All three are 30A. I'm beginning to suspect the genset breaker is weak.
FYI if you're working on this over the phone, the genset breaker works and feels like a soft switch. It doesn't click into release, have to be pushed farther to reset, or take a lot of pressure to latch it into the ON position. The lever simply moves.