Mobile nav menu not displaying

We recently upgraded from V3.7 to V4.5.6. I did the update manually via ftp after deleting the old enfold theme folder. (I do have a back up but would prefer to get this resolved)

Currently the burger / mobile nav does not display so whether I set the main menu to hide at mobile or tablet size the menu hides but the burger menu does not display.

I can see in the code in enfold.css there is this code that is hiding the menu. In the inspector if I uncheck the CSS below then the burger / nav menu shows.

@media only screen and (max-width: 1167px)
nav.main_menu {
    display: none !important;
}
}

I have cleared our cache plugin cache, also turned it off, cleared cloudflare cache, in the theme settings under performance I have disabled merging and compressing css, I have checked the box delete old css / js files, updated the mobile nav settings to the different options and I have updated the CSS in quick css and clicked save. None of these things seem to resolve the issue.

Just trying to figure out why the menu doesn’t work and how we can get it to work without overriding your code?