Tyre pressure monitor

After the last tyre pressure adjustment, tyre pressure indicator started showing red and indicating that the front right tyre had a pressure of 2.3. The other tyres had 2.2.
As the obpverpressure was insignificant, I did not worry about it.
But suddenly the multi screen started showing the message "no cal". I assume the pressure sensors are not callibrated????
Shall I go and adjust the oressure to 2.2 on all wheels, and then callibrate the system with the button below the dashboard?
Or?