MIELE KF7654 SNE Temperature Sensors

I have a MIELE KF7654 SNE Fridge Freezer Nr 57774940. It was giving an F4 error code so I got a new sensor, part #9590206. Unfortunately when i installed it I mistook F4 to be the air sensor so I replaced that and then discovered that F4 was the evaporator sensor. So I then removed the evaporator sensor and attached the sensor that used to be the air sensor.
This removed the error codes so I set the temp to -18 and turned on the freezer. The freezer display dropped to -18 but it was really approx -4 when I tested using a standalone temp reader. If I set the freezer to -28 and turned on the super freeze the freezer display then read -32 but the real temperature is -18 .
I then measured the resistance of the sensors by removing the circuit board connections and testing them.
The two sensors gave very different readings. For instance with the new 4.7K ohm sensor (placed in the air sensor position) has a much higher resistance than the original working sensor (placed in the evaporator position)

at 0C (placing sensors in water bath)
new 4.7K ohm sensor 16.4K ohm
original working sensor 12.4K

at -15C (freezer says -30C)
new 4.7K ohm sensor 44.2K ohm
original sensor 15.1K

at 16C room temp
new 4.7K ohm sensor 7.1K ohm
original sensor 2.9K

So the new sensor always has a higher resistance than the original working sensor
For the record the original bad sensor reads 200ohm at room temp.

When the freezer was at -15C and the freezer display was reading -27C I placed the new sensor in hot water at 50C, the freezer display stayed at -27C! Very confusing.

Is the 4.7K sensor the correct one for my freezer?
If the two sensors have very different resistances will this confuse the freezer?
Why would the freezer display not rise from -27C when I placed the air sensor in hot water?
My assumption is that all the sensors in the freezer are the same, maybe that’s a bad assumption.

Any help would be very much appreciated,
Conal