Hamburger menu stopped working on iPad or iPhone

Hi, my hamburger menu has stopped working on mobile devices; everything is fine on PC.
I’ve deactivated all plug-ins, cleared cache, deleted and recreated the main menu, and nothing has worked so far.
What’s going on?!
My website is

Ok, I’ve got it to work by deactivating the child theme. I hadn’t made any changes to the child theme yet, just set it up the other day.

Why would the menu in the child theme not work correctly? It was obviously a direct copy…?

I also noticed that the scrolling text in the header didn’t work in the child theme.