Secondary menu works great EXCEPT when on the Checkout Page. It shows the same selection on all pages except for some reason when on the Checkout page it is showing the top bar menu items and not the same selection as on the rest of the pages? Not sure why?
Theme issue when you chose custom menu for the page http://prntscr.com/e3m0rp
If you don’t use menu for the page different than main menu then you don’t need to chose it like custom navigation in page settings. Also, we’ll try to fix the issue with custom menu and secondary navigation in next theme update.