Hello Per, please check this one:
How to set up Eve Thermo including the Offset

Important note: The temperature displayed below Target Temperature in Eve is measured by Eve Thermo way too close to the heater, please ignore it. Once an Offset is set, it will not be integrated here.

To set up Eve Thermo open the app Eve and goto
Settings > Accessories > Eve Thermo
Set Temperature Offset to 0 degrees.

Then in Eve goto Rooms > Eve Thermo and open Eve Thermo.
Set Target Temperature to 23 degrees for example and let it heat for 2-3 hours.
Then measure the temperature in the middle of the room with a thermometer, Eve Degree or Eve Room.
If it reads for example 20,5 degrees, goto
Settings > Accessories > Eve Thermo and set the Temperature Offset to -2,5 degrees.

You may have to adjust this over the next days a bit.
As stated before, the Temperature Offset is not taken into account in the temperature shown below Target Temperature.

This should do the trick, best regards, Volker
Feb 4, 2021