Problems with german letters like üäö in menu in firefox

Hi there,
i did a onepager and got a menu in the Nav thats called "über uns".
in the frontmatter i wrote:
title: 'über uns'
menu: 'über uns'
All works fine in Chrome but in Firefox the hover doesn't work anymore.
When i rewrite it like:
title: 'ueber uns'
menu: 'ueber uns'
Everything works fine in Firefox, too. So is there any solution to use ü? Maybe somebody allready had the them Problem?

Again tricky to debug without being able to see the site directly :(

Tried to send pm but it always says "No staff currently online."

https://dl.dropboxusercontent.com/s/bse782ghaa8y8qi/2017-03-23%20at%203.19%20PM.png

Can you check if there are no special chars hidden inside the word? Sounds weird I know, but maybe you copied the text from MS Word. Just delete the word and rewrite it inside your text editor and see if it works.

Again this appears to be something related to JS and the target #uber_uns. There's clearly some JS that is trying to modify the menu with an .active class based on the fragment link.

I think in Firefox this is conflicting and it's causing both of your Firefox fragment (#) link issues. It's not a Grav issue for either case though as it works fine in Chrome, and all Grav does is output the HTML/JS/CSS etc. That is clearly working fine, the rest is your web development side. so really beyond the scope of this Grav-related support forum. Sorry.