So we hired a contractor to have a new bath/ shower combo installed. Yesterday I saw that there's water in the corner after I took a shower. This morning contractor came and we checked inside while the shower was on for half an hour and we found no water dripping inside. So we decided maybe water went inside the tub spout and dripped down from there because I saw there's a hole in the caulking. But then after he turned off the water, recaulked the tub spout and left, I went to look again, now I can see the corner is wet again, so looks like its not the piping or tub spout! The caulking of the shower wall seems fine. Then what's the problem? Could it be the tub drain? Because now I know its after the water is turned off then water slowly sips through and I can see water at the grout of the corner tile in front of the tub. I so hope that the contractor could see that... :(

What can be the problem??? Does anyone have such experience?