No surprise there, I bought a couple of typical 50k nominal NTC thermistors on my last Digikey order, they were about 60 cents easy, no big loss. On the bench in a 76F room, they're around 46K, if I grip them between my fingers, they drop to 30F, and if I hit them with 100C air from my hot air tool (measured with a K-type thermocouple), they drop to 4.5K. I can hit them with air from my compressor and they shoot up in the 80's and 90's quickly.
Move the thermistor a bit farther away from the smoke resistor, and also make sure both the smoke resistor and the thermistor are firmly in contact with the wick material.
I'd be closely checking the wiring between the smoke unit and the RCMC board, and failing that being the issue, I think you may have a bad RCMC.
