[NoBot]

The Specs for the WH03242 are HERE.
They show voltage as 120V -- not 240V and not 120/240V
Download the Manual and you'll see the 30amp outlet is:
"120V, 30A RV – NEMA TT-30R
A maximum of 26.7 Amps current may be drawn from this receptacle."

 

[NoBot]

His generator has a maximum wattage of 3,200 running watts - 4,000 peak. Specs say 26.7 amps at 120 volt = 3,204 watts,
This generator is undersized.
My microwave is 1,550w, toaster 900w, coffee maker 1,500w = 3,950 watts and we haven't added a furnace blower motor, refrigerator, freezer, lighting, etc.
When I install a Reliance GenTrans, I always recommend 7,500 watt generator minimum with a 30 amp, 120/240v twist lock.
Using the 10 circuit GenTran, you could turn off all circuits except one or two and try that.

 

[NoBot]

When you wired the Gen Tran, did you connect the red wires to the breakers?

 

[NoBot]

With a Gen Tran by Reliant. Red is line and black is load.