Nav Menu not working iPad Portrait

Hello

I have modified a theme (Louis Wp theme demo:https://themefurnacedemos.com/louis/) and created a website https://bargdvd.co.uk where the menu is not showing when in iPad Portrait (i.e. at 768px wide).

In the Louis theme demo (https://themefurnacedemos.com/louis/) the menu goes into mobile version at 959px wide, but for some reason it isn’t working on my site.

I have modified the css much in terms of the menu (and especially not in terms of with @media queries)…could one of my plugins cause this result or is it a styling issue somewhere?

many thanks in advance for any ideas or suggestions ??