Thanks for the wait. I took a good look at this today and will need a little time to work up a solution for you. It’s really easy to make the header sticky on mobile. The challenge is that the mobile menu is bound to the original top menu. When you see the sticky menu you’re actually seeing a duplicate menu called a sentinel. So the challenge is to also provide the mobile drop-down menu in that second header. I’ll need a couple of weeks for this but should be able to provide a solution for you. We might need to internally rework some aspects of the mobile menu’s code.