I have the very same issue and to make it clear: i’m using Origin theme too, and the breadcrumbs on topic page have a link to forums list (works fine) and to forum which those topic belongs (don’t work).
Even creating a blank page with the shortcode [bbp-topic-index], how to use same slug (WordPress automatically puts a number 2 in the end)?
Forums list (working fine) http://www.memoriabit.com.br/forums/
Forum (not working) http://www.memoriabit.com.br/forums/forum/sega-mega-drive-genesis
Topic (working fine) http://www.memoriabit.com.br/forums/topic/super-monaco-gp/
Thanks in advance.