We took our DRV to Kansas RV Center to take care of all our warranty issues before warranty runs out. Our closet ceiling had developed a gap. Rick at Kansas RV said that all the weight on our closet rod was causing the closet ceiling to sag. You can see the small gap above the closet rod in the picture below (upper right corner of picture).
They fixed the gap and added a board to support the rod from the floor.
If you full time and have a ton of clothes hanging on your closet rod (like we do) you could do this mod yourself. The closet rod goes directly thru the board and the board is secured at floor and ceiling of closet.