Search Redirects to Front Page
This issue consists of any search in the bbPress forum search from either the search form above the forum index page, the topic index page, or the bbPress forum search widget, to somehow redirect to the front page of your site.
Causes
This could be user generated issue by the user editing the forum search slug in Settings > Forums in the Single Forum Slugs section. Some users have made the forum search slug something that involves two words with spaces in between them like say “forum search”. In the end while using this slug would output a url with something like %20 in place of the spaces, and it would almost certainly redirect to the homepage every time.
There is some cases where disabling the forum root slug in Settings > Forums could bring up the same issue.
Solutions
Edit the forum search custom slug in Settings > Forums to something without spaces, just replace the spaces with, for example dashes instead like (forum-search).
If you disabled the forum root slug in your forums, either enable it to no longer have the issue, or change the forum search slug to something besides the default slug “search”.
If the issue still remains, please make sure you have gone through the plugin and theme issue resolutions stated here: Troubleshooting