For $10 get a GFCI outlet tester
Plug it in to the outlet and check for ground and polarity. The most common error installing GFCI's is to connect the hot to the load side of the receptacle. If the GFCI outlet is wired backwards (hot on load side load on hot side) it will not reset.
If your generator isn't tied in to the main panel how are you getting power from it into your system? Based on your comment "GFCI resets but all outlets show Hot/Neu Rev
" It sounds to me like you are feeding the gen power in through another receptacle on the same line as the GFCI which would put the hot lead on the proper side of the GFCI if it is wired backwards so it will reset. It also sounds like your gen is providing power on the neutral side of our system which is dangerous.