Hello Armin / Marius,
I don't know how this story ended, but I got quiet the same problem with a website I am working on. I am not a developper and I only got some notions in HTML/CSS/JS, so i'll try my best to explain.
I created a fixed button on the top of my homepage, wich leads to an anchor lower down the page. First things, depending from where the link is clicked, it add /#nameofmyanchor or only #nameofmyanchor. I don't get why does it leads to 2 differents URL
Then when I go to some other page on the site and I come back to the home page with the browser previous buttons, it leads to the same page i'm on with #nameofmyanchor at the end of url (forexemple works/#nameofmyanchor instead of home/#nameofmyanchor).
I have to click a second time on the browser previous button to go on the right page.
Is there a solution to this issue ?
Thanks a lot for your attention :),
Théo