I came home after a couple of weeks away and my smart shunt required an update due to updating the victron app on my phone. I am not sure if the update caused the problem (it could've failed prior to my return), but the voltage reading is very wrong ever since. at 27v I am seeing 21v, for instance. I pulled the hot lead from the unit and let it reset, verified the voltage on the wire is correct with a DMM, which matches the reading on the charge controller, and after cleaning everything up and getting it all back together the voltage is still a half to full volt lower on the smart shunt than reality.
Is there a way to revert to the older firmware on the smart shunt to rule that out or anything else that I can check or do?
edit: I added a second wire to the 'starter battery' port, swapped wires, etc. The second port indicates the proper voltage consistently, the main port wanders all over the place low and high, regardless of which wire I use in which port. I think it's just toast. Initiating warranty claim.