Can't attach to, or extend my main large grid anymore
I started a new survival game two days ago, no mods. I proceeded to build a nice house, making many adds and removes overtime. Then I decided to remove a shelf, and tried to put it somewhere else, but I couldn't. In fact, after some testings, I realized that my shelf wouldn't attach anywhere on my house, including to its original spot.
I reloaded my game file, with or without exiting to Windows. It didn't help. I started a new game in creative mode, and then, I was able to add shelves to walls normally. I reloaded my first game, the problem is still there.
Shortly after that, I also realized that I couldn't add anymore walls, roofs, supports, or anything else to my house, and that any object such as chest, crate or spinning wheel would bounce off the surface as a moving object when I tried to drop them on the floor. Has my main large grid somehow changed state? Turning into a giant dynamic object itself? Immobile, only because it is stuck in the ground? Or is it just a bug?
Simply by creating a new large grid (building a wall in the grass away from my house) I could add shelves normally there.