handyman needed to replace a single tile

Wild Orange Gate near Linden lithicum, Columbia MD

Description

A bathroom floor tile somehow got loose such that the tile can be pushed down (see attached pictures). And ants were spotted coming out of the gap created by the loosening of that tile. I guess that somehow the cement board (or whatever backer board) below that tile got eroded to the extent that the tile became loose. I would like to see that tile as well as the backer board there-below get replaced by a new tile so that new tile would be tight and secure like the neighboring tiles.