2010 Town and Country climate control

[sb68]

Having an issue with the climate control. Everything works fine but after driving for awhile the air will gradually start diminishing coming out of both front and rear vents to the point it gets almost nothing out of the vents. Both blower motors are still working because I can hear them and they both change speeds from low to high. I just don’t know where the air is going. If I shut the van off and let it sit for awhile it will start working correctly again next time i start it up. I have a feeling since it happens to both front and rear simultaneously that it may be the climate control unit itself but was hoping maybe someone has run into this issue before.
This is the manual control unit not the automatic.
Also, I was wondering if there is a climate control reset/calibration procedure for this particular style. Having a hard time finding much info about it online anywhere.