I found something that kind of scares me.
It looks like they had repaired a crack in the wall and then covered it up with a layer of concrete tbat has broken away now.
When I removed the old wall
Studs I noticed they had the wood right up against the concrete and I left a 2" x 2" gap the entire height of the corner where this problem is.
Any ideas? Looks like the repaired crack is still sealed and my only guess is with the gap left in the corner caused some kind of condensation which weakens the concrete plaster. I could be wrong. Lol