Air flow at ducted vents not working

[Damon08]

Hello everyone,
i'm looking for some input regarding a 08 Damon outlaw 3611, with 2 Carrier V A/C units. The RV is fully ducted and right now we are going through a 100+ degree heat wave and the cooling system is not keeping up in the least.
for some reason the first 4 vents are blowing heavy, then the next pair feel like someone is breathing on you, then the next single is blowing like the fan is on low, and lastly the pair of vents at the bed nook is barely working.

I have pulled some vents to see if there is blockage, and i feel air pressure, but for some reason the vents are not directing it?

Is there something I can do to increase air flow? or do I need to install another A/C Unit on the roof?
Please Help!!!

[Travelin' Texans]

Be sure the vent portion that's into he duct is not so tall as to block air flow beyond it. On last 5th wheel the duct was about 1 1/2" tall into a 1 3/4" duct work, trimmed them down & used aluminum duct tape to seal the opening & duct work so it wasn't cooling the attic.

[16ACE27]

Since it's an 08 I assume this has worked correctly in the past. Pull the inside cover of your A/C units, check the filters (duh) but more importantly check the divider plate between the suction and discharge to make sure it hasn't fallen down and can't get up. If the divider plate is not correctly in place the discharge air would much rather take the direct shortcut to the suction side of the fan rather than travel all the way down that ducting.

[Damon08]

Thank you for the replies. I checked the duct work with an inspection camera and everything looks to be sealed and clean of any blockage.
I also pulled the filters and checked to see if the divider plate was still in the correct spot "it is"
I then went ahead and climbed up on the roof and removed the shroud to check the coils and all the lines to ensure there wasnt blockage from anything.
I think I am going to upgrade to 2 15k btu units for the added oomph, but I am worried that the ducting may not be able to handle it. I imagine that back when this was being made and sold they had the option to install 15k units with the same ductwork. Possibly even add a 3rd on over the bed and remove the manual vent. Any advice would be appreciated.
Thank you!

[cavie]

close the direct down dump vents on the A/C cover in the ceiling.