Reply To: BuddyPress 12.0.0
@erotmil this is a public forum, do not share access to your site. I never ask to log in to a user site, and I’ll never log in to edit a user site. I just deleted the access you shared in your previous reply.
Your custom page is out of BuddyPress scope. The only thing that has changed since 11.4.0 that could possibly interfere imho is the fact BuddyPress used to put its JavaScript and Styles everywhere on your site, including this page. You can try to use the gist the way I commented it to have these JavaScript and Styles back.