Well, I think I fixed it.
Decided to gamble $10 bucks on a new circuit breaker.
Installed it three days ago and so far everything has been working like it should.
All 12v systems are working, battery stays charged and when I disconnect from shore power the inverter will power the fridge.
Mounting bracket on the new breaker was 90° off from the old one, but no issue making it work.
Thanks again for all the input, will avoid running the slides and jacks at the same time in the future.