There was a problem with the pipes under the floor, which resulted in several ceramic tiles being removed. At the moment these tiles are back in place. The problem is that 2 tiles next to them, that weren't completely detached, were glued back by injecting typical silicone under them. The problem is that now they balance a bit when we step on them.
The silicone method was suggested to me, and didn't work well. The tiles are being slowly taken off, moreover the tile grout cracked several days after because of that little movement.
My only idea is to inject some more silicon under the tiles, and fill the gaps using typical grout.
How can I glue these 2 tiles back without taking them off?
Note: There is a fair amount of silicone under the two detached tiles, there is no point in injecting tile grout.