In order to get an answer we need more information.
Size of floor joists--spacing--unsupported length-
subfloor material and thickness
What did you use for a backer board? Did you use thinset under it?
What brand and type of thinset did you use?
Size of floor joists--spacing--unsupported length-
subfloor material and thickness
What did you use for a backer board? Did you use thinset under it?
What brand and type of thinset did you use?