As far as I can tell it’s the consequence of the ground and foundations that aren’t deep. My neighbor suggested it had something to do with some kind of activity nearby, which is why it affected all the houses tho she couldn't remember the specifics. There was also a train line that used to run not too far away, and is now discontinued
The rear of the house (where this room is located) was stitched over 12 years ago, and the elderly person who lived here just didn't repair or renovate. I’m not sure if there’s any more movement occurring, but there’s not damage around the stitching
JJ, what makes you think it hasn't settled? And yeah, I will bring in a professional to take a look.