Not OP, but was camping with him in Animas.
We had three rigs at the same location, two with REC panels, two with EG4 inverters and their integrated charge controllers. There were several other rigs in and out as well, that never had issues (none of those with REC or EG4).
No other rigs had...
Upper left rig has 4x EG4 LifePower4 100AH, we had them on USE for several days due to error 61 and it did not have the same issue. Error 61 resolved and of course, no issues now either.
Rig in question has 4x AmpereTime 12V 300AH batteries in series with a balancer, USE, 56.8V bulk and 54V...