Since you are using the FN-DC relay, my suggestions are:
Check the FN-DC wiring harness, make sure all the connections are still tight, all the way to the generator.
Reset MATE3 and FN-DC and redo the programming, starting with one single trigger point, for example:
Voltage start only 2 minute setting
As you validate that each step is working, then you can start adding additional triggers like must run. If this does not work, I would move the AGS to the inverter AUX, however, remember that AUX is a signal 12V 200mA.
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