Sounds to me like some connection is lost or damages somewhere ( like a cable broke somewhere). So the most pain in the ass work to fix.
I would use some fresh cable and go direct to the panels, see if this works, if so you know at least that is the reason. Cheapest way IMO to check.
I am still leaning on a loose connector, when I did a continuity test they tested fine on the underground cable. So next is to check those connectors one by one.
Eventually we will try some replacement cable. But for now I plan on starting on the more basic things like tugging on each connector.. lol
thanks for the tips
yeah is pain in the ass work.