But on my page the navigation is not floating on the left site. wehlen.mehlhop.com Insteat it is fixed on the top left.
What I need to change to get the navigation floating so it is always visible on the left?
Could be that you just needed to clear your browser cache. I find more and more these days that there are times that I have to clear it every single change I make, and then other times I don't touch it for weeks. No idea why, but browser cache is a pain in the arse, and is many times the culprit in these cases.
I agree with Jo, the browser cache on Chrome can be a real PITA. I've discovered that if you open the inspection window in chrome, you can then right-click on the reload icon and it will give you the option "empty cache and hard reload." This seems to be the most bullet-proof way I've found for clearing the cache on a page you're having issues with.