What was the water proofer on the shower floor and the walls ?This looks like awet room install so all the floors and walls needed to be waterproofed properly. I think it might be that the material used under the tile was not dried yet. I do nt see the black stains or do you mean whatever is in that 2nd photo. Did you run water in this shower ? The tile is not grouted so I sure hope you did not run water in ther e.

@Patricia Colwell Consulting The tile is already grouted, we used a steel grey epoxy. We ran water few days after laying grout. Waterproofing was done before laying the tiles(Dr Fixit - a reasonably good brand available here in India). The first two pics show a sort of water stain which is not drying out. The third pic shows the blackish blotchy stains.

Update: the tile shop where we got the tile from, sort of agreed that the problem could be due to tile quality. But, no solution to this problem.

@User Iam not sure, the gap between laying the tiles and doing the epoxy was close to one month. Isn't that enough for curing? And besides, spacing the tiles and putting epoxy btw them is the right thing to do, isn't it?

How's the tile now, any update . Have the similar situation. Been 2 days now not drying up

We had to remove the floor tiles and lay neenew tiles. This time we used vitrified tiles.