Flooring is by no means beneath me, but I haven’t really done anything below a shoe molding. So question for the tile high club: What would you do in the pictured situation? These are floor sections that have always felt a bit “squishy”. Today they finally popped up into the tent formation you see here.
Wait for it to settle and then add glue to keep it down? Cut it to fit?
Additional context:
I did not do this install myself, so the history is a bit of a mystery. This is installed in a full bathroom and is made of what feels like a smoothed slate material. I believe it is a composite tile.
More photos for context:
The main concern about an unlevel floor is why is it unlevel? If you can figure out the "why", that will tell you if it's easily fixable or if it will potentially get worse.
How hard it is to investigate depends on how accessible the underside of the floor is. It's going to be pretty hard to tell from the top side without ripping off the tile first.
If the room has a crawlspace or basement underneath and you feel like playing detective, get a bubble level and go check the joists and beams in the vicinity. Work downhill until the slope stops. That will give you a general area of the source of the problem.
There could be a variety of causes, some of which are obvious, some not as much.