Tiles Bulging Off Wall
Since the tile is flat and in the same plane the wall surface must also be a perfect match.
Tiles bulging off wall. Damage to a subfloor is one of the most common reasons for a tile to bulge or lift from the subfloor according to the american society of home inspectors. Make sure that the tile adhesive that you use is water resistant. The wall isn t hot to touch difficult one to answer as obviously the shower is running at the time but the problem does occur on the side of the hot water upright feed each time. As ceramic tile get larger the wall or floor surface must be flatter and flatter.
Grouting has been done too early. The chalk dust will stop the tiles from adhering to the wall. The adhesive needs to be applied evenly and on every tile. The subfloor must be clean even and dry before tile installation.
A buckling or partly raised tile on your shower wall usually means water has gotten behind the tile often through cracks in the grout and caused the wall material to expand pushing the tile outward. A pull down that section of wall and re tile with new blue board etc although the current old tiles cannot again be sourced to match the exisiting. I feel this in conjunction with skinned over adhesive is the root cause of your tile failure. Adhesive has not been applied properly.
B replace the removed tiles with a large mirror c force the wall back in with some type of ugly metal alloy strip screwed in over the top of the tiles and into the stud. Any low spots on the subfloor can cause a tile to bulge. Tiles need to adhere to a smooth undamaged surface.