Do you have a battery disconnect switch?
Maybe it's off?
Are you able to test battery voltage?
I've seen new batteries go bad.
You didn't specify how long you've had the rig only that you bought new and everything was working perfectly... but for how long?
Test the voltage at the battery.
A fully charged battery is usually around 12.6 to 12.8 volts DC.
Leave the meter attached to the battery and plug in the camper and see what it reads.
Voltage should go to somewhere around 13.4 to 13.8 volts.
If it goes up, your converter is working and should charge your battery.
Again, if the battery is bad, even though the converter tries to charge the battery, the battery won't hold the charge and needs to be replaced.
2016 Flagstaff 8529IKBS Diamond Package 5th Wheel
Ford F-Series SCREW 4x4
TST Tire Monitor - Sinemate 3500w Gen.
2016 Nights Camped = 44