A/C vent problem on Melbourne

[stumpshot]

We've been camping in our '16 Melbourne for a month now and I've taken care of most of the problems that bothered me but I've run into one on the A/C I don't want or know how to handle.
The house A/C unit has 6 roof vents, 3 down the passenger side and 3 down the driver side. The pass. side vents are working fine---nothing from the driver side.
I've shut the vents on the A/C body, etc and nothing helps. I pulled the inside cover on the unit and found a piece of cut-out, foil one side, plastic one side, insulation lying in the unit floating around. I pulled it out but don't believe it had anything to do with the problem.
Could a duct not be hooked to the plenum? This is going to be a dealer service unless someone knows an easy fix.
Thanks,
Stumpshot

[Grumpy]

Has to be something stuck in the plenum, probably a piece of roof material. You need to remove the entire plastic ceiling assembly to find it.

[Shakedown St.]

With no access, it will be tough to track down. May not even have been connected, but it also could have been crushed during the ceiling install.

When you close all vents except the problem ones, and close the vents on the unit itself, is there any airflow through the problem vents? If not, then its disconnected. If there is a little then it's probably restricted.