CUNY Academic Commons

Fixed for now, will follow up later.

The problem was due to an update to the search-everything plugin. It appears that the plugin author is aware of the issue: https://wordpress.org/support/topic/v-8-1-8-hides-all-posts-in-bbpress-forum/

I don't believe that the search-everything plugin was in active use for anything on the main site anyway, so I deactivated it there.