Yes, separation would be a better word. What I first noticed is the sealant applied when the plastic corners were installed was adhered to the side and the corner trim edge was a 1/4 inch away from the sealant. The corner trim is not loose, it's as if the back wall is separating from the side wall, corner trim moving reward with the back wall. As I said it's about 1/4 inch at the bottom and barely noticeable at the top. My fear is that there is wood underneath and moisture has caused it to swell. I have not yet taken steps to start disassembly. I was inquiring as if anyone else has seen this. I won't be able to post pics. for several days. If my explanation here does not make sense I know the pictures will.
Thanks