Breadcrumbs or Forums problem

Hi there

here an picture i want my forum:

how i dit it?

i get an new site and add shortcodes like [bbp-single-forum id=3234]
…

now the breadcrumbs are linking on the “original” root “/forums” link… so i have think, ok, make an site with the perma link on /forums/ and add the shortcodes…

but when i dit this, my site looks like this:

so, can you please help me change “only” the one breadcrumbs to my custom site, or what can i do the “originally” “/forums/” works correctly with the shortcodes?

thank you very much

greetz