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:
This is the correct answer. With all that mortar, the rest of the tiles are sure to come off too eventually. The whole thing needs to be redone. Take out all tiles and all mortar. Subfloor needs to be properly prepped and then you can lay the tiles back correctly. There's enough information online to do it yourself or you can hire someone.