Hey Chris
Can you give me some details of your installation.
Especially the lenghts of cables, cross sections, connections, placement of the additional cappacitors.
I had the same failure twice. My first thoughts had been also the same:
Should shut down automatically
internal safety algorithms
Couldn't bei damage without mechanical impact
...
But last but not least, high internal currents habe killed my MGM twice. In the end it is now working very stable.
But it was a very expensive and hard way...
Would like to help you
Bye Fabian
P.S. self developing should be the best in the end