after your last set of answers, and now knowing that you had the Inverter OFF when this happened, that you have lost HALF of your 50a power supply from the Power Pole you are plugged into...
50a RV shore power is actually TWO hot lines, both 50amp, giving your coach up to 100amps of shore power.
Half of this goes to side 1(left) of your breaker box, with it's own Main 50a breaker, and the other goes to the other side.
It sounds as if you have lost HALF of your 50amp power, one 'LEG', as you have 'some' power and not some other.
Look at your breaker box labels. See if everything that is working is on one 'side' of the box... if so, this is your answer - a bad 50a power connection at the Shore Power pole.
now, this could 'either' be the power itself, OR it could be your shore Cord, which may not be making a good connection on one of it's brass Connectors.
just my guesstimate... have a park owner/employee check your 50a shore breaker, and whether both of the lines are 'hot'(120v).
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