Yep that is a recent issue with my Multiplus 2, started like 2 weeks ago after all the power outages.
Checked wiring on my side, all good.
Suspect issue on Munic side.
2 solutions:
1.An isolation transformer providing a new neutral.
2. Timer activated contactor, when.ac in is on, delays ac out for 2 minutes.
Pondering which one. Best I can get an isolation transformer is R4000, timer contactor should be cheaper if only I can find a supplier that has some grey matter