You could be sitting on the wedge incorrectly. You can place the steeper side of Gokhale Wedge to the front and see if this helps. You may also need to work on your stacksitting technique. Pull your buttock flesh back as needed and make sure your back is not swayed.
Learning the Gokhale Method from a video or textbook is like learning tennis or golf without a coach. We strongly recommend taking one of our basic courses (Online “Elements” = 18 x 13 minutes or our In-person “Foundations Course” 6 x 90 Minutes with a qualified Gokhale Method teacher.
You can watch this video to get a better understanding on how to use wedge in stacksitting:
https://gokhalemethod.com/video/how_use_gokhale_wedge
You can also book a follow-up session with our online Gokhale Method Teachers for a more comprehensive evaluation of how you sit:
https://gokhalemethod.com/online_initial_consultation