[scottktmrider]

It looks more like movement. in my house when I bought it the previous owners converted the carport into a bedroom that's on a concrete slab. every winter the wall that connects to the house the inside corner the tape looks like yours. than when the weather warms up it goes back and looks like nothing ever happened.I figured its movement in the slab

 

[scottktmrider]

Hello Scott, can you further explain movement? It seems to happen when we open the windows for couple of days straight and in high humidity. Since this happened, we see it once in a week or two, but nothing as near pronounce, just tiny bit, barely noticeable. This is with windows close and a/c on. It would come and go. Some further information, the only think I can think of was a poorly plaster job done and the high humidity just screw it up. Also, you can't see from the picture, but the blister is along the border that divided the newly repainted/plaster ceiling and the original /plaster ceiling if that makes any sense. It seems the previous owner did some paint job or sort on half the ceiling.

I had concrete movement, sounds like you have wood expanding, you might try a de humidifier, or put an expansion joint in the ceiling, lol

 

[scottktmrider]

If you are going to try to repair this I would use a quality tape like no coat or straight flex