Check for loose wiring connections in the generator electrical junction box. If it is OK there, check the wiring in the transfer switch. What other loads do you have on when testing the ACs?
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7