I swapped out the entire unit (probe, display, cords, outlet). None of the same parts as the original.
I have a third that I'm going to swap probes and see if that affects it.
I just had a similar problem, but it was with two of them. One read over 100 degrees and froze my lager. I swapped it out with a unit that was controlling another fridge (working fine). When I checked the next morning the new one was reading 116 and the lager froze again.
I'll work on...
I live in SW and brew fairly regularly. I have an electric BIAB in my basement to allow me to brew all year long. I'd be up to see how others do it, especially if its so close.