Language Switcher / Top Button Disappeared

Hi, I’ve been working on my agencies new website for a while, and I had a language switcher implementation and a top button that both worked. I did a bit of intense layout work yesterday, and suddenly they both aren’t visible anymore.

Can anyone help me out on this? I’ve tried increasing the z-index, but that didn’t fix it. Time’s running out on the launch, and it can’t go live without those features.

Thanks in advance!

EDIT:

How it looks in preview mode:
Bildschirmfoto 2020-05-15 um 11.05.33

And here’s how it looks on the live site:


Here is my site Read-Only: LINK
Here is my site Live: LINK
(how to share your site Read-Only link)

So I managed to fix it by taking the overlay elements out of the luxy Smooth Scroll Wrapper. This seems to work just fine.