*** FIXED***(kind of)*** I know it’s been 8 years since this was active but I’ve been banging my head for DAYS trying to figure this out and HERE’S THE FIX!!!
Download the plugin BBP Style Pack https://wordpress.org/plugins/bbp-style-pack/ after activation go into style pack settings open the “Freshness Display” tab – check the ‘activate freshness display’ box and then change the freshness format from default to display the date on the last post. Save changes and that’s it. If you leave the setting on default it will not work. You will have the same problems. It needs to be changed to ‘show date of last post.
I HOPE YOU CAN RELAX NOW