According to page 10 in the 2018 Cougar Eastern brochure, every half ton fifth wheel is equipped with the "Race Track Duct System".
The system is shown in a diagram on page 6 in the same brochure and clearly shows how "Cougar beats the competition" with their "inferior separate systems"...
I'd first do as Chuck suggested and pull the front A/C ceiling unit to verify the presence of ducting runs on both sides of the air conditioner. If you do find the ducting runs (and I'm sure you will) then IMO, it's time to have a "sit down, heart to heart" with the dealership general manager with the service manager as a "silent observer"....
Here's the link to the brochure on the Keystone RV website:
https://keystone-rv-dealer-app.cdn.p...chure-2018.pdf