no air from center dash vents

[srtfool]

hey everyone, a little help please! i have an 07 xlt, manual tempurature control, and for a few weeks now each time i turn the truck off and back on again i have no airflow coming from the vents in the dash facing forward. no matter what the position of the knob, it only blows out of the defrost and floor vents. it has plenty of power so thats not an issue. however heres the weird part, once the trucks been running for a few minutes, or driving, the center vents magically open up and the air comes out perfectly and everything works 100% fine. that is until i turn it off, then back to square one. i just replaced the blend door actuator figuring it was that and not a thing changed. so any help would be appreciated. im stumped

 

[lounge lizard]

is the blend door it self sticking in it's housing??

if the actuator can't push it, it will take longer for it to open.

some where there should be cabin filters in the air vent system. I've yet to find mine! LOL

but maybe they shifted and have pressure against the blend door, which is making it open slower?