This has been an issue since around the time the AudioGames.net forum migrated to PanBB, but it never really impacted me much so I left it. It appears that PanBB broke the navigation menu at the top of the page when displaying in its mobile view. Before migration, there was a link with what I believe was a multiplication symbol which expanded the menu, but this functionality does not seem to be present now. This can be especially frustrating when trying to use the forum from a device such as an iPhone, or in my case, if you're stuck in the compact mobile view for some strange reason.
Edit: Fixed typo in topic subject.
from The Book of Mozilla, 11:14