Circuit breakers on Inverter.

The inside panel breakers and the inverter breakers are actually totally different circuits.

The invertor has a transfer switch in it. When you are plugged in to shore power (or running the genny), power is supplied to the invertor from the inside breaker panel (30 amp on ours) Inside the invertor, this powers the battery charger and (on ours) a pair of circuits with pushbutton breakers on the magnum inverter itself.

Unplugged, the inverter powers those circuits from the battery bank.

There will be outlets in your RV that are not on one of the inverter circuits, you just need to go looking.
With the inverter ON, shore power unplugged, look for outlets that don't have power. Those will be the ones not running thru the inverter.

Just a note, your going to kill your inverter by overloading on a regular basis.

Different size breakers... you may have two items on that one circuit and sum of those two breakers inside are greater than the one on the inverter. Stop overloading or buy a bigger inverter.

Inverter breakers are more sensitive. Don't overload it.