That's a strange problem but it's not the IQ. The IQ is a very nice little unit, don't give up on it. I've heard of grounding issues with other generator/ TT combinations. Someone more knowledgeable than I may be able to shed some light. With an ammeter, you can definitely rule out issues.
The iQ should run just about everything but the AC and Microwave at sea level. With a few simple mods, you make crank the 13.5 BTU AC. Some folks are running them with 2000 watt units. A hard start capacitor and time delay on the fan will knock off about 10 amps of the starting surge. But that's after you figure out your immediate issue.
Rockwood 2104S, 2014 Ram 2500 Diesel.
USMC 68 -70