No Air Flow Through a Single Vent

[FUR259]

Hi Everyone,

I have 2015 C Class. I just noticed that there is no air coming from the left side vent (Passenger's side). I have closed and opened it many times but there is no air. The remaining vents (3 on Centre Console) and 1 on driver's side are fine. It is same for hot and cold air. When I raise the setting of air pressure to 6 or 7, I hear whizzing sound from that vent.

Any Ideas?

Thanks