Hopefully resetting that mini breaker will have restored your charging of the batteries from converter at least. When charging you should measure at least 13vdc across your coach batteries. I would also confirm that the coach batteries will charge from your alternator as well (engine running with shore and gen off).
A multimeter is a very valuable tool for all RV owners to help test for correct charging of batteries and trouble shooting electrical problems. Any digital multimeter will work and you don't have to spend a lot to buy one. I am attaching a video which describes the basic use of a multimeter. You don't have to buy the one shown in the video and you don't need auto ranging (it is a nice to have feature). Also note when they show measuring ohms (resistance) and continuity, it is very important to not
have any power on the circuit/device you are testing or you can damage your multimeter or blow a fuse in it. Also note that multimeters have small batteries inside that occasionally need replacement. Similar to TV remotes etc.