[JRTJH]

That was my thought as well. Even though the battery started out at 12.4 VDC and ended up at 12.1VDC, if the leveling system started one motor, then while that motor was running, started another motor, the actual voltage to the controller circuit board could have "momentarily" dropped to 11VDC in a "negative spike" that wouldn't have been "measured before turning it on and/or after turning it off".....

The point I'm making is that even though the battery voltage "measures" 12.4 VDC before leveling and voltage "measures" 12.1 VDC after the event ends, that doesn't eliminate the "potential for a drop in voltage DURING the operation.

If that is occurring, there's a good chance that a "weak cell in a battery" or "corrosion on a wire connection" or "high resistance ground from corrosion" could be the problem and it would likely not be identified with "before/after measurements"...