Deco Lav vanity sink drain issue....?

[Antalamo]

I installed 2 Deco Lav vanity sinks. I finished it off with 2 Hansgrohe widespread faucets that included the drain assembly. The problem I have is the drain outlet flange is not sealing at all. Hansgrohe provides a gasket and does not require plumbers putty.

The only thing I think could be an issue is the drain hole has a slight contour around the edge possibly causing the leak. My question is if anybody has had problems with Dec Lav and would it be recommended to use their drain assembly. I figured Hansgrohe to have a higher end assembly but it does not work in this case.

PS: I used plumbers putty in place of the gasket and it leaked worse. Maybe I need a thicker gasket around the drain outlet flange???

 

[hj]

In another location you say the "contour is at the rear" implying an assymetric design, but here you say it is "around the edge" implying symmetry, which would be a completely different issue than a "tear drop" shaped recess. WE would have to see the drain hole to determine WHY you are having the problem, since I have not had that problem even though I ALWAYS use plumber's putty, or the supplied gasket.