Hi Jannis,
I’m having a little trouble getting a MapBox style to work. They’ve changed their interface since you did your demo page and I can’t get it to work.
Closest setting I can find to your demo: https://cl.ly/90ed0f4a23e5
RW OSM settings: https://cl.ly/d3cb3d160927
Published page: https://www.scale-ni.russam.me/contact/ (to left of contact form)