I have a tile that moves slightly in my shower(moves down, not side to side-talking millimeters, not much), on one of the sides the grout came out, so I need to patch it up and reseal it...anyone have any product recommendations before I go to HD?
Sounds like a bigger problem, whenever tiles "move" or grout cracks, you have an issue. It certainly shouldn't be moving down, send a picture. Sounds like water is getting behind, need to find that first to figure out how expansive the repair will be. May have already compromised the substrate
Just a note, it doesn't move enough to even see it...the only reason we noticed it was that we could hear the little air bubbles forming...so it's not like the tile is loose and flopping around or even moving in a way that could be felt or detected by the naked eye.