Are you sure your microwave is on the Inverter?
I have a 2018 Outlaw 29H with 3 TV's and the same inverter. Only the TV's are wired to the inverter from the factory. The microwave is not. I know this is a Class A vs Class C but a 1000W Inverter is unpowered for a microwave.... let alone adding 3 TV's to it.
If that is truly the case, there may be a wiring issue and the Inverter is somehow related to your problem.
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