Does this sound like your symptom?I continue to have this issue as well. This is super annoying. Can't pinpoint it for the life of me, but it is certainly something that only happens after you drive it for 10 to 15 minutes. I am due for a cabin filter change so I'm going to try that solution and report back if it helps me any.
Quote: n. The HVAC blend door motor / air door actuator directs the flow of air in the vehicle’s cabin. If the motor burns out or the shaft cracks, the “door” can get stuck in one position, leading to improper ventilation
Here is the part: Part Number: 27732-A070A
INFINITI QX60 Hvac air door actuator. Hvac mix door actuator. Hvac temperature door - 27732-A070A - Genuine INFINITI Part
Hvac air door actuator. Hvac mix door actuator. Hvac temperature door actuator. INFINITI QX60. Genuine INFINITI Part - 27732-A070A (27732A070A)