Probably either the door frame or the door are twisted. On our Sunseeker the door does shut flush. But when the door is open, I can eyeball it and see that the door is curved at the bottom. I figure maybe the builders intentionally twisted or bent the door a little to make it line up with the jamb.
2020 Sunseeker 2440DS on 2019 Ford E-450, Trekker cap, Topaz paint