Air flow does not go out in front position

[hcch]

Hi I recently noticed that in my daughters KJ when selecting the vent to flow front or front-below I can only hear the fan running but no air flow is coming out on any on the front vents.

I will apreciate any guidance on this matter.

I couple of months ago I replace one aftermarket 1 din headunit for a 7 inch 2 din one, and used the Metra adapter I do not know if that may have somethng to do.