The only "goofy" questions are the ones you do not ask!!
Not sure how the two relate here. The solar panel is likely a small trickle charger for the battery. It is designed to MAINTAIN a fully charged battery as it is too small to do anything else. What indication do you have that it is no longer working??
As far as the "inverter" is concerned, I am sure you mean the CONVERTER. An inverter is connected to 12V (battery) and puts out 120V AC to run, for example , a TV set while not plugged in to a power source. The CONVERTER, on the other hand is connected to 120V when the trailer is plugged in and outputs 12V to charge the battery and help run all the other 12V things in the trailer like lighting, furnace, Fridge and Water heater control boards etc.
Few trailers are equipped with an inverter other than the small ones intended for operating a TV, almost all have a converter. There are larger Inverters that can charge batteries however, but they are not usually found in small trailers.
I am not familiar with a Jayflight trailer though, perhaps someone who is will pop in and explain the panel in question.