Your converter isn't working properly to keep the battery charged and provide 12V power, and the loads are consuming the battery charge. The problem "fixed" itself because the house battery got charged from the engine alternator while you were driving home.
If basic troubleshooting doesn't reveal something simple like a loose wire or a blown fuse or popped circuit breaker for the converter, it probably would be as well to simply replace it with a good multi-stage unit as I suspect the factory converter is a simple single-stage converter. A newer multi-stage one will recharge the batteries faster and be gentler on them once they are charged.