No nav menu on a custom post_type screen

Hi all, so I am using a theme that for some reason doesn’t support nav menus. After a bit of fiddling I’ve got it integrated into the nav menu system and I can use the GUI etc to manage menus fine.

This works on all static pages, all posts etc.. Except one type. I have a plugin installed called “The Events Calendar” by Modern Tribe. When I browse to the upcoming events page (a crucial page to have) the nav menu completely disappears. Checking the source of the rendered page shows the PHP i run inside the header.php page to generate the nav menu simply doesnt return anything, it is blank between the UL tags.

Now I’m completely stumped, as I don’t know why this would happen, I dont even know how the plugin is generating this sort of page? What page is it? I dont know where to start.

Any advice??

Thanks all, Dave.