Check how much Plugins and stuff you have going on at your WP website.
Lets say you have a Sidebar at the page that also has to query for, latest Blog Posts, Comments, Topics and Replies than it all takes a lot of performance.
I need more help with this. Last night I disabled all my plugins, I reinstalled bbpress, noone has had this problem before?
Try to install some Debug plugins they will give you some answers about why things take so long to load.
https://codex.wordpress.org/Debugging_in_WordPress
– at the bottom is a list of good plugins.
I’ve been experiencing similar results for a few months now, BUT only on topics with more than a few subscribers.
It seems that BBPress is waiting for a confirmation that the email notifications have been sent to subscribers BEFORE it releases the rest of the php script and allows the page to refresh for the actual person posting.
The post is actually posted very quickly if you look at the forum on another browser whilst the browser used to actually post is still processing.
I’ve set up a TRAC ticket here and have been investigating it for a while.
https://bbpress.trac.wordpress.org/ticket/2162#comment:8
I’m wondering if there is a better way to handle the notifications?
I’m no coder though unfortunately.