I'm using mmenu.js (v9.3) with a single-page site - it all works, with the pageScroll add-on allowing same-page links. BUT my fixed header is not fixed until you click the menu hamburger and close it again. And in desktop view the hamburger is display: none so no way to make the header fix, even if I could live with that.
In older versions of mmenu.js there was a fixed header add-on, but this is no longer an option, presumably integrated into the main code.
Not loading mmenu.js returns my header to fixed so I know it's the culprit, and I have no errors in console.
Anyone come across this and found a fix? Better still is the author out there? - I paid for a multisite license.