1Dot that's expected. There is a "load more" button in case the infinite navigation doesn't trigger.
This could happen if someone has a large screen or zooms out so that multiple "pages" are visible. In that case Flarum wouldn't be able to tell if the user is reaching the top or bottom, so it simply shows a button so the user can manually trigger the loading in the direction they need.
That's not specific to this website, it happens on all Flarum forums.
