MEP – 002a out put not consistent

During the latest power outage my MEP 002a began to produce odd current. I am connected to my home and shop with 3 phase power. Sometimes when an outage happens only one or two legs go down and the result is some things work, some things don’t, and some things like lights just glow. That is similar to what happened while connected to the generator some lights kept blinking . It happened, I think all of a sudden and persistently even after shutting it down a few times. I did move the phase control from 3 phase to the single phase positions and back with no luck. Anyone have an idea what might be wrong? Thanks, Andy