Does the trailer have a battery on board?
If it does, that would be the most likely suspect.
Assuming there is a battery involved:
When hub turned off shore power and left some interior lights on, those lights drained (possibly shorted) the battery.
A dead or shorted battery will draw more power than your converter is capable of supplying. There's nothing left to power any lights. All breakers and fuses could be good, with lights not working. If battery is still good, the converter will take a very long time to recharge it.
Steps I would take:
Turn off shore power, remove the battery, and put it on a charger for 24 - 48 hours. Then have the battery load tested. (If you're new at this, label the battery cables to be sure they go back in the right place, and note the + positive / - negative positions on the battery)
While the battery is out, turn on shore power and check lighting.
Note: There are a few older converters that require a battery being installed, in order to power the lights. If your's is one of them, you'll need to wait until you have a known good battery.
Your converter will look
something like this.