Top Menu tab limit

I am using the Travel Lite theme on my website https://www.nakedeyetravel.com
There seems to be a limit on the number of tabs that can be used within this menu: 88 if I counted properly.
Every time I add an extra tab the last tab in the list falls off the menu.
So if you look at the site at the moment, the last tab is ‘Blog’.
If I were to add a tab called, say, ‘Facebook’ before it, then ‘Blog’ would drop off the end of the menu.
Is there any way to change this or to increase the number of tabs that can be used on the menu.
Any help you can provide will be greatly appreciated.
Thanks,
Craig