Battery dead

Kellercarol

I have 2 6v brand new batteries that I’ve used for a few months. I drove 4 hours to camping using the battery for fridge while towing and switch immediately to propane upon arrival. I
did not check charge. Upon returning that night battery panel showed low and the cig lighter monitor showed 19. I did not have my generator so waited til am. Now panel shows full charge and cig lighter 14. Now 13 I can’t log into Victron as new phone and pm isn’t working
nothing is on except propane fridge which I now have off
any idea what’s going on?  Why pawl says full charge (maybe just solar and
not batery?)

Kellercarol

Kellercarol

It’s a 2020 400