How do I fix this old wardrobe?

We have an old wardrobe that is set up to be disassembled. There are no nails needed, it’s mostly wooden parts sliding neatly into grooves.

Ever since we moved, this wardrobe seems to be unbalanced. Two of the doors drag along the bottom and can only be closed by lifting them slightly. They’re already removing the finish where they drag.

I know this is a long shot, but…any thoughts?