Usually when you go into a sub-forum you can just select the "Forum" heading at the top (in red) and go back to the main page. Under the Help forum however this has been changed to only go to the "Support" page.

A mistake I think.

It depends when you last visited the support page. If you visited there recently the site thinks you came from there.

If you haven't visited there in a while it'll think you came from the forum.

I hope that makes sense.

Thanks Dave. That's what happened.