No AC shore power to RV

[imolared]

Howdy,
Prepping for trip, leaving Friday AM.
Montana 3120RL 2019
Minutes ago the ref switched to gas after running on AC all day.
The surge protector shows 124V
Not getting AC into the RV
Starting the generator, puts AC throughout the RV, appearing normal.
I reset all circuit breakers.
There must be some sort of fuse or breaker between the shore power line and the circuits on the RV before the generator
Looking for ideas.
thanks,
-ed

[ChuckS]

If the generator is an installed unit then I would be looking at the transfer switch and RV cable end connections