Spiny Norman said:

This seems odd. I first thought it might be a bit of slippage from an earthquake but nothing looks to be shaking.
Any ideas?

https://x.com/i/status/2001325956062183554

Earthworks contractor here.

This is a failure of earthworks/engineering. There is too much movement under the slab and the engineer hasn’t specified the correct footing details. In short, the house slab has cracked as the ground underneath it has subsided/moved.