Sounds like the Dealer may have told them something that you weren't aware of that led to Rockwood declining coverage. Rockwood has usually been very good about warranty issues. I think the dealer holds the answer.
45 Years RVing and no end in sight.
2018 Ram 3500 SB Limited, CC, 6.7/Aisin, 4X4, SRW. Comfort Ride Energy Absorbing Hitch.
2020 Cedar Creek Hathaway 34IK, Reese 19K Sidewinder PB.