I moved my forum to a new server by downloading the backup from the old server and restoring it on the new one.
When I logged in after the restore, I noticed that the navigation bar that was sitting on to of the discourse header (similar to what we see on try.discourse.org) is not showing so I checked my custom HTML/CSS and found that all the code was there and that “enabled” was also ticked, but the navbar was nowhere to be seen.
So I tried disabling, saving, enabling, saving and indeed: the navigation bar came back.
Next, I found that the links that I had added to the hamburger menu were also gone. The same trick worked here: disable, save, enable, save. However, once the additional links showed up in the hamburger menu, the navigation bar disappears again. Even after a rebuild, I cannot seem to have both.
Another thing that might be related but went away after a rebuilt was that most (all?) of the settings (such as a custom contact URL or the authentication info for facebook or google) were not shown under site_settings. Nevertheless, they seemed to be active anyway (for example, the contact url was correctly shown on the about page. I’m not sure if is expected behaviour that these will only show after a rebuild but I thought I’d mention it.