I'm at wits end with a small repair to a bathroom ceramic tile floor.

I had to secure about 50 2" x 2" tiles that had become poorly attached. Original bond was thinset, but I believe the movement of the floor over 15 years created the issue.

So, I decided to use the ceramic tile adhesive to replace them.

After one week, some of it has dried and some of it has not. The material that has dried is not thoroughly dry and the tiles can be moved slightly.

The material that never dried (six tiles) allowed me to lift the tiles right off the floor. I applied new adhesive today and will see if it will be successful.

What I don't understand is why this material fails to properly dry? I've used it before with similar (poor) results.

Anyone else have this issue?