There can be different reasons for this.
The Wi-Fi socket contains electronic components that generate heat. This can in turn affect the sensor if the socket is placed in an incorrect way. The temperature sensor is located at the bottom left corner (when viewed from the front) to ensure it is positioned away from these heat-generating components.
If the Wi-Fi socket is mounted upside down or facing left, the heat from the components may affect the sensor's readings.
For optimal accuracy, it is strongly recommended that the Wi-Fi socket is installed facing downward in the outlet. If this is not possible, it should be positioned facing to the right.
If the socket is mounted correctly but still displays an incorrect temperature reading, it can be calibrated in the Mill app using the following method:
Open the Mill app
Go to Settings (bottom right corner)
Select Calibration
Choose the device you want to calibrate
Adjust the temperature accordingly