sub menu in sub menu

For our website https://wwww.tnt-events.nl we need to use a sub menu in a sub menu. Currently there are 2 options in the main navigation; ‘Welkom’ and ‘Evenementen. There is also a blog function but that is not relevant for this problem.

For the page ‘Evenementen’ we have a sub menu which displays correctly ‘Skutjesilen’ and ‘Esprix’. However in these menu’s we need to create another submenu. Plese find the menu below:

Welkom
Evenementen
– Esprix
– Skutjesilen
– Q&A

We have created this Q&A page as a child under ‘Skutjesilen’ but this page is not displayed in the navigation menu. No visitor can access this page. Does anybody has an idea how to display the Q&A page? I have removed the sidebar function for pages since I do not want this to appear on any page except for the blog. It should be visible under ‘Skutjesilen’ in the normal navigation of the site.

Thanks!