I spent 30 minutes with the multimeter and concluded the probe is fine, but somewhere between the probe and the solder joint, there must be a broken wire, couldn't get consistent readings.
I went to the hardware store, bought 20 feet of copper solid core/2 pair/ thermostat wire. cut the wire 4 inches above the probe, wrapped, soldered and double wrapped the splices, re-ran the wire in the conduit and I think it is working.
Funny how the wire that comes with it is stranded and it is fragile somewhere, rather than buying a new probe, I did repair this one. Now to wait it out to see how it works.