Primary Menu Text Spacing with Sub Menu

Hi. Is anybody able to help me with this? I've created a primary navigation menu but when I add a sub menu item it affects that primary menu item so it appears ranged right compared to its background fill (ie it butts up against the right hand side). All the other primary menu items are fine and unaffected. As soon as I remove the sub menu item it is OK again. Thanks in advance.

I've tried changing the navigation and inner navigations widths from contained to full but it doesn't correct it.

This page shows what I mean https://tinyurl.com/y9p8sduz

I'm using a child of v2.0.2. premium