It's a complete mystery to me how my 3D printer build plate becomes unleveled.

Usually it stays in place for days, over multiple print jobs. Often it even raises itself, tightening the gap between nozzle and bed.

Then other times it'll drop what feels like a whole millimeter in the minute between leveling it and starting a print. Nothing but spaghetti.

I'd really hate this if it weren't actually easy to manually re-level the bed.