i have four tiles that look as though they are rising from the concrete.
Sounds like you've got 'tenting' going on. A picture or a better description will help. It would also help if we knew the size of the room and among other things how it was installed and with what products,
TILE GUY - retired- TROY, MI - Consulting by phone/internet - PAYPAL
DITRA Installs - KERDI Watertight-Mold-Free Showers. I have NEVER made a mistake, I thought I did ONCE, but, I was WRONG!A+ BBB rating - est. 1987 - over 50 yrs. exp.