I didn't read all the comments. At the risk of repeating someone, your door latch issue may be easy to fix.
The
door strike plate on the door frame is typically held in place with two screws. These are usually not sheet metal screws. They are machine screws into threaded "nuts" built into the door frame.
If the screws aren't REALLY tight, the door strike can move....relentlessly moving farther and farther into the door frame and making it harder and harder for the door latch to slide into the door strike.
Solution: Get yourself a REALLY GOOD #2 Phillips Head screwdriver...say a Milwaukee or similar. (Maybe you already have one.) Something with a perfect, super-hard tip. Use it only for this and similar jobs so you don't strip out the phillips head screws. Press in hard with your body weight on the handle and loosen the two screws. Slide the door strike plate toward the outside of the door frame, then tighten the screws using the same method in reverse. My guess is the screws aren't going to be all that tight when you loosen them, but when you tighten them, you want to apply considerable pressure to the screwdriver.
This is NOT a job for an impact driver. Use hand tools only. If you strip out the "nut" on the door frame, you'll really regret it.
DO NOT use Loctite on the screw threads. The strike is held in place by friction between the door strike and the door frame. This is less a matter of the screws coming loose than it is the strike sliding over the door frame due to relentless pounding by the latch mechanism. Loctite will make next year's adjustment...inevitable...just that much harder.
Using this method, I still need to adjust my door strike about once a year. When I notice that I have to start slamming the door, I make the adjustment, and the door works perfectly for another year.
Someone mentioned lubing the door latch mechanism. Yes, do that. But if you don't want your clothes to get greasy, don't overdo it. Use something like aerosol silicone grease deep inside the latch mechanism...and MAYBE a tiny dab of vaseline or similar on the rounded surface of the latch and the door strike. But the narrow doors on RVs mean your clothes
will come into contact with the lubricant. I don't lube surfaces that my clothes can touch.
My hunch is that, assuming you haven't abused the door, there's nothing wrong with anything...no warping and so on. It's just the door strike out of adjustment. And, unlike exterior doors on your home, the weatherstripping on an RV door must be able to stand up to rain and road spray coming at it at 60 MPH or more, so the weatherstripping is pretty robust. Compressing that weatherstripping very much with a misadjusted door strike is very difficult.
That's my 2 cents...might be right...might be wrong. Check your door strike adjustment before you chase a warranty repair. This would not be a warranty item. And if this is the problem, Jayco sure isn't going to pay a shop for a 1 hour minimum to perform this adjustment.