Hello, has leak in my bathroom which was leaking into garage. I cut into my ceiling in garage and the leak was from the shower drain. Went to shower and removed cover for drain which was easy, was able to lift up with a pair of pliers and no turning required. Was intending to check the gasket and make sure it was actually on but instead i found like a white thick material between the drain and drain pipe. Looks like a white clay that got hard to cover the gaps instead of a rubber gasket. is this an acceptable thing? what is it and do I use more of it to fill in some of the gaps I see? If more info is needed please let me know and thanks in advance, appreciate all the assistance.