Does your fan speed vary? Is it the volume of air not changing despite the fan speed varying?
I had the situation where, due to low refrigerant, the evaporator coil was icing up blocking the air flow despite the fan running on high speed. When everything was turned off for 10-15 minutes the icing disappeared and everything would be fine until it iced up again. An AC shop checked the system for leaks, evacuated and refilled the system.
If it is simply the fan speed not varying then change the FSR (Final Stage Resistor) as it is usually the most common failure point.

__________________
Sent via Telegraph Wires using my Morse Key.
2021 X5 xDrive40i
2015 X5 xDrive35i MSport
(Traded) 2013 X5 xDrive35i