We had a custom steam shower installed approximately 4 months ago. Recently, we noticed that the grout (or caulk???) that was used on the perimeter of the shower is very soft and pasty, and is crumbling away. This is occuring in areas where the wall meets the floor, as well as where the tiled shower bench meets the wall. Any ideas on why this would happen and how we can have it fixed? Also, will this crumbling problem result in water leaks outside of the shower area?