As you have bbpress installed in forum directory, thats why its showing one more forum
if you have installed it in example.com, then only one forum would be shown
(though you already know this)
To fix this, you might do this (NOTE: I have not tested it, nor do I know if it might have a side effect on anything else, and this change will also be vanished when you upgrade bbpress):
Open bb-includes/functions.bb-template.php
Go to line number 711
This would be written there:
$link = bb_get_uri('forum/' . $forum->$column . $page, null, $context);
Change forum/ to category/ or anything you want.
You also need to change that at line number 847 and 819 for rss links.
You also need to change bb-admin/includes/defaults.bb-htaccess.php appropiately and regenerate permalinks.
I would like to hear what others have to say on this.
i’ve solved partially this problem moving bbpress in a subdomain
