I found this problem on a car today:

A/C works fine when climate set to MANUAL & LO (2.9 degC at vent)
A/C works fine when climate set to AUTO & LO (2.9 degC at vent)
A/C switched off and climate set to LO (13 degC out vent = ambient)

As soon as the climate is set to anything else than LO then hot air 26 degC air is blown out whether the air conditioning is on or off.

Has anyone ever had a fault with the interior temp sensor?

Could the climate display be faulty?

Any help would be appreciated !!