Hi
I have had the same experience. My 2015 Fleetwood Southwinds has been at the dealer (we keep a calendar) longer than I have used it. This time it went in for sidewall cracks. This was very serious to me and many phone calls to get Fleetwood to allow to be fixed at the dealer. I know you can take it to the factory but I am not retired and do not have the time to go and wait. I understand your pain and it should not be this hard for the large amount of money we spend. Think about it we use our cars every day for a cheaper cost and they are covered for 3 to 5 years. We use the RV 14 to 21 days a year with one year coverage. I think they are engineered and built to fit the one year warranty. I think most people give up on getting fixed and that is what the manufacturers counts on!
The dealer and Fleetwood should honor your problem as it was reported before your warranty expired. Keep up the fight and you will win but it will not be easy. I have a good dealer and still have issues.