Well I can’t unplug it, it’s hard wired in but I can kill the main on the pole

Any chance that’s a digital thermostat and it has a backup battery of its own?

Negative

I had all kinds of electrical issues with mine. I can't remember all of the details but I changed the thermostat, a couple of breakers, fixtures and switches and still had random issues. Shortly after this all started, a guy that used to work on campers told me to change the converter. I should have listened. After a few months and a few hundred $s, I finally bit the bullet and ordered the converter off Amazon. I changed it out myself and have had no more electrical issues since that day. I'm not saying that the problem is the same with yours, but I'd definitely keep it in mind as you search for the answer.

Well chit I guess I probably need to order one especially being an older camper anyways.

NOTE; I edited my response above, apparently after you read it.

Do you by chance remember what size converter you ordered?

No I don't, but I looked inside the cover and found the brand, model # etc. I'm thinking it was maybe either 3000 or a 3500. It's for a 30amp hook-up. That much I remember for sure. It came with all new breakers for somewhere around $300-$350.

Oh u bought the whole power center not just the converter.

That is correct.

Pull the cover off the thermostat & check for loose wire connections. I had this problem myself.

Also pull the outlet and make sure the wires use the screw in parts and not the push in connections.

the first thing I'd do is go buy a meter (voltage tester)

Thermostat wires are all still good and connected. I do need to pull that outlet and check it. I plan on taking a volt meter when I go back down there I have a new thermostat that’s identical to the old one so we shall see

that should help. The only thing you want be able to check with the meter is the batteries capacitance. A bad battery can still read 12V's. Like an old cordless drill battery. It'll charge up. But it wont work because its lost its capacitance. I don't know the first thing about RV's but Im guessing there's a way to test that. Unplug charger. Put a load on battery and check voltage drop. Depending on the load and time you could probably get a good idea of the batteries cap.

also if you know what tstat wires do what you could probably jumper them with the meter lead ends or touching terminals with 2 small screwdrivers and crossing the metal shafts.

Check propane sensor if it has one. On my Montana it is on front of cabinet underneath fridge. On mine if it sense leak it will shut electrical down.I might have took a power surge or something. The warning buzzer/beeper wasnt working but light was blinking. I jumped mine out to test it and everything worked.

Microwave still works so it doesn’t shut down all electrical. It’s almost like it overloads or isn’t drawing enough power after a few min. One wall of camper is on a 15 amp breaker the other side is on another 15 amp breaker.

Does the camper have slide outs?

I’m going to bet the wire has pulled loose from the plug. They are just jammed Into the slots. Pull the bad outlet and look at the connection