If above ^ is right then it means you don't have an automatic cut-over between shore power and generator. You can test this by disconnecting from shore power, starting the generator and see if your AC only items (microwave, air conditioner for example) will run. If they do, well then you have a cut-over device. If not, STOP the generator, plug into that 50A outlet, then restart the generator and try the AC devices again. Please report back what you find so others can learn.
2016 Forester 2401R