I am remodeling a shower at my home, installed new acrylic shower pan with Kohler K9132 drain assembly. I cut the 2" PVC waste pipe per the instructions for the shower pan which said to cut it 3/4" below the subfloor. However, after installing the pan, and fitting the rubber gasket down over the waste pipe, the gasket bottoms out in the drain body after going down only about 3/4" onto the waste pipe. The drain instructions say to push it down until the top of the gasket is flush with the top of the waste pipe, but in my case the top of the gasket is about 3/4"above the top of the waste pipe. I did check it by pouring a bit of water around the edge of the gasket and it seems to hold after 15-20 min. Question is, is this acceptable? Am I asking for issues down the road such that I should pull everything out and extend the waste pipe before I get any farther along? I'll try to attach a picture, hopefully it works. Thanks for your time all.