Does anyone know why a TFA Dostmann temp/humidity sensor reading would differ from the temperature displayed on the indoor unit?

I changed the batteries this morning after the outdoor temp read 25C at 9am. I tested the old batteries and they did need replacing. I fitted new batteries but just noticed that the reading on the sensor says 20.3C/80% humidity, while the indoor unit display reads 16.7C/80%.

At least the humidity is accurate but why is there a difference of 3.6 degrees C between the indoor and outdoor readings?

The sensor is a TFA Dostmann, model No TS34C

(I did reset the sensor after fitting the new batteries)

Problem solved, a silly mistake on my part. I must have pressed the `set` button, so the display was showing `dewpoint temp` instead of `temp`. Hence the discrepancy.

There is no indication on the display whichever temperature parameter is being shown.