CumminsOnan RV QG 5500 Fault Code 15...

I just received a Fault Code No. 15 (Underfrequency Fault - Engine governor unable to maintain rated frequency). Output is about 112V so we're a little low there. Anyone have experience with this situation?

Gen puts out power to run refer (not the Colorado type) and microwave but shuts off power when I turn the AC on. If I shut the AC off, power comes back on.

Gen is HGJAB-901 Spec J unit.

Thanks in advance!!!