I'm trying to build a vertical fixed top navbar with Bootstrap 4 Beta. I have found on the web several examples of Bootstrap v4.0.0-alpha.6, but they do not work with Bootstrap 4 Beta. I have the problem that when the navbar assumes the fixed-top class the links and the the collapsed navbar move to the left. Below are links to html image with code:
You can see the menu behavior and code at this address: http://www.fedelemarcopascuzzi.it/verticalnavbar/
I am experiencing the exact same problem! The behavior looks a bit like it thinks the display is small and is rendering the menu as if it were on a phone.
Edit: Alpha samples don't work, this code is working for me: https://getbootstrap.com/docs/4.0/examples/navbar-top-fixed/