I Changed R56 for 56k Ohm, so the 5V bus is at 5,3V (instead of 4,9V), but this was not the issue, I think
What I think I did wrong with the previous 2 inverters:
In my test setup, I don't have a negative contactor, but I have used the service disconnect (temporally) as most negative disconnect.
Thinking back, I forgot at the start to plug in the service disconnect (both inverters), and then I applied 12V to the inverter, and the precharge circuit closed.
Then there will be 180V at the inverter but no connection to the battery negative.