I hope this post will save someone’s time. Let’s say you have a super great WordPress theme and you have been using it for your BuddyPress site. Today you want to to style BuddyPress pages differently than a regular WordPress page. You have followed everything written on the official BuddyPress docs. You have moved all the BuddyPress legacy templates files inside your theme your-theme/buddypress and you have created buddypress.php inside your theme directory to style BuddyPress pages differently than your regular WordPress page. But you found out that it was using the page.php instead of buddypress.php.
If you are in this situation, you will probably want to check your theme functions.php. Look for the ‘add buddypress support code’ and delete it.
add_theme_support( 'buddpress' );
Now go and reload your page. I hope this solve your problem.