Travel Trailer blocking RF (Garage Door Opener)

I'm with JKWilson.

Unplug the trailer, see if the problem stops. If it does, then it's probably the converter - and at that point it's a scavenger hunt.

Plug it in, turn off every breaker.
One at a time turn them on and test to see which circuit is the culprit.

The only thing I can think of is the converter broadcasting RF causing your problem.