No clue from the info given to us. Post pictures and that may help but we would really need to know about the wall and current frame conditions.

"Interior door not closing"

This is function and has nothing to do with this;"These are really ugly flat panel cheap doors."

So, you can either describe the problem, with the "function," or spend the money to replace.

My concern is that at one time they did actually close. I noticed when we have had issues with doors not closing in our very old house, it meant something else was going on, as in the level of the floors were shifting. It's to be expected here in a high subsidence area with a two hundred year old house and with some of the original doors the shape of trapezoids and not rectangles have seen how the doors have been modified over the years to match the frames. LOL.