Mobile: Second dropdown menu does not open right away when first is open

[kerolol]

When there are 2 dropdowns present in the navbar and I'm in mobile version, I can not directly open the second dropdown-menu, if the first (and in mobile, the upper one) is already open. What happens is, that when I want to open the second, lower navbar, it closes the first one. Only then I can open it with a second click.

Menu with the first dropdown open:

Menu after click on the second dropdown (you can see the hover-state of the search button as my cursor lands on it after I click on the second dropdown link and the first dropdown closes):

I took the menu from "Starter Template" from the Examples page to codepen.io and added a second dropdown menu to reproduce this issue. Codepen example can be fround here: http://codepen.io/kerowan/pen/LxKmER

EDIT: Realized that I first had the ids aria-labelledbys set wrong (left it with dropdown01 for both dropdowns) but fixing that does not resolve the issue

[kerolol]

Found an exisiting issue for this behaviour ( #21941)