How to Reset A Danfoss Temperature Control To Be Getting Realistic Readings?

>Is there a way of resetting this control to be giving real temperature readings?

I doubt it. You're on your own to reconfigure it.

Several things to check:
1) The document is unclear as to sensor types. It says Pt/PTC/NTC. I would interpret PT as a probably a platinum RTD, PTC as a positive coefficient thermistor and NTC as a negative coefficient thermistor; all resistive elements. But the selection options only appear to have Pt/NTC/Pt. Typo?

If the sensor type is wrong, your temperature reading will be incorrect.

Without vendor support to identify the sensor element type, one method would be to change the setting for the type of sensor until the controller temperature indication reads correctly with whatever a thermometer tells you is the correct temperature. I'd disconnect the controller's output while experimenting so the compressor motor isn't trying to start multiple times while you try different settings.

2) The unit can read in either Fahrenheit or Centigrade. If -4°C is 25°F, so positive Fahenheit temperature values can easily appear to be negative in Centigrade.