Tabbing through main navigation

The tabbing through the main navigation on the site does not go through in the expected order. Currently, when you tab from About it goes straight onto Sign Out. 

The expectation is that when you tab from About it follows the following order;

About -> What Do I Need To Do -> What's Changing? -> What Is Open Access
Could you change these quotes to single quotes? Same for `"href"`. The tests seem to be failing on these although they shouldn't..