Hope someone can help. I moved into a property A couple of years ago with an extension that was built in 2013 so not old.
In the corner of the wall there was a bulge and when I dug down I realised it was like a grey plaster that was cracked.
So I patched it up with plastering tape and a ready mixed filler. Now a year later I’m decorating and I found it’s buckling out and cracked on the surface in about the same area and when I opened up the crack it took off a layer of plaster exposing wood underneath which I assume is the plaster it’s frame?
I’m not sure what caused the bulge in the first place but should I be concerned and what would be the best way to repair it?
See pictures attached. Many thanks for any help. (Apologies I couldn’t rotate the last picture So it’s on it’s side.)