I don't know anything about this unit, but from what is shown, you have power from the
solar cells, but they aren't charging the
battery. When you go to AC the
battery is showing discharged and the converter is charging the batteries.
Is this a stock setup or did you install it yourself?
In either case, read the manual. If it's a stock setup, check with the trailer manufacturer. If you installed it yourself, double check all of your connections.
We could all be more helpful with more information. Right now we are limited in what we can suggest.
Clif