I used a 1/4” notch trowel and those levelling clips. All tiles easily popped the next day.
I switched to a 3/8” notch trowel and they seem firm. But I’m nervous carrying on laying tile over this heat system.
I’m no pro, but I have done 4 or 5 floors in the past without issue. I’ve always used a 3/8” notch trowel and never used levelling clips.
The only difference here was using the recommended 1/4” trowel, laying on top of mapeheat system and those levelling clips.
My guess is with the 1/4” trowel, the tiles didn’t compress into the mortar enough and landed on those clips.