I have the same problem – have just put out a support request.
Hi @theoctupusgardengroup – I figured this out for my site.
Have you made any changes to the CSS?
I had
.main-navigation ul {
position: relative;
left: 100px;
}
to centre the menu items on the desktop.
As soon as I removed this, the view on the mobile reverted to show the menu items to the left of the screen, instead of offscreen.
You could try
.main-navigation ul {
position: static;
}
in ‘Additional CSS’ and see if that works for you.