Hi Debra - I'm not sure what's wrong with it, but here are some videos on repairing a rounded corner wall:
If the damage isn't too severe you can fill it with Spackle following the curve of the corner then let it dry and sand it with a foam sanding block. If the wall is textured you can either use a spray texture product like this.... https://amzn.to/2XNw8xt to blend it before painting. We used this on our wall when we patched where we had a wall air conditioner installed and it works really well.
If your wall is only slightly textured you can also try a thin coat of spackle then blot it with a damp sponge (or put spackle on a damp sponge) to create slight texture and blend it into the surrounding undamaged corner. Honestly once it's painted I bet no one even notices.