I am having this same issue. Is it possible that a membership plugin would interfere? I am using Digital Access Pass. I can see the options on the profile edit page, but nothing on the topic pages.
Just chiming in here for the record. My knowledge of code and plugins is novice at best and I’m afraid I will not be of any help.
I received these 404 errors with a fresh install of bbPress a little over a week ago. My membership plugin, Digital Access Pass, kept tripping it up. The DAP support team did some testing and could not come up with a solution for me. They suggested I use the fix from https://bbpress.org/forums/topic/fix-404-issue-for-bbpress-2-2-x/ until something else could be figured out.
I’m no expert, so take this for what it’s worth and research further …
Here’s the code I found that seems to work. Have not fully tested. Would appreciate any feedback from someone with more experience.
In form-reply.php
Find bbp_the_content( array( ‘context’ => ‘reply’ … and change line to
` ‘reply’, ‘quicktags’ => false ) ); ?>`
In form-topic.php
Find bbp_the_content( array( ‘context’ => ‘topic’ … and change line to
` ‘topic’, ‘quicktags’ => false ) ); ?>`
