First,verify that shore power is indeed absent,, Do the air conditioners blow air if turned on in fan mode? If so you have shore power.
Outlets may run through inverters,, If that is you have an inverter, Many inverters have circuit breakers on them (not always easy to find) and the rest have a "Sub Panel" somewhere (Second breaker box). Mine is the sub panel type.
And finally: on my inverter if I turn off the master switch, located the unit itself (As opposed to the switches on the remote panel) OFF is really OFF, no power passed the box, not even pass through.
IF this is not your problem you need to search for the fault:
You need to start at the source, Get the proper adapters to plug your "Little yellow thing" into the park outlet,, Use a volt-meter at the RV end of your shore cord.
Locate the auto-transfer switch (I found mine and dang near passed out, There is one spot in my RV which is the most logical place for this switch to be and ... IT IS THERE!!!!!, Talk about shock).
Meter the shore leads CAUTION DANGEROUS VOLTAGE PRESENT.
Meter the output of the switch
meter the main circuit breaker(s) to the white bus on the power distribution panel (Same Caution)
If you have not found the problem by now you need more assistance than I can give remotely (i'm much better hands on)
I have found many RVs have a few screws loose.. Usually in the electrical system
Home is where I park it!