What is the voltage at the A/C terminals when both are running? My CBs get much warmer than 105F. You have bad breakers, bad A/Cs, bad wiring/connections or low voltage or some combination. You might want to get a get a AC clampon ammeter and also measure the amps.
I run all 3 AC's in 120F weather plus whatever else I want w/o any issue on shore or gen.
Not sure why you're attempting to repair a 2019 unit but be careful that you don't void your warranty.
If you do decide to by a clampon then get one that measures both AC and DC amps.
