Look inside the circuit breaker section of the power supply unit.
I had a similar issue with our previous trailer. It turned out to be a short inside the breaker box. Multiple wires had insulation melted and even one wire the copper conducter was melted in two!! I came scarey close to a fire.
If it's still under warranty, get it back to the dealer ASAP for sure.
FAA A&P mechanic, ex-RV dealer parts dept
Retired B-52 Gunner/Flight Examiner, B-52 Crew Chief
2016 Jayco Eagle HT 29.5 FBDS w/ 15,000 BTU AC, 50 amp service, upgraded counter top, thermal pane windows, elec. stab jacks, outside grill, backup camera and MORryde pin box.
2011 GMC 2500HD DURAMAX/ ALLISON