remove_activity_comments_override.php

<?php 
add_filter( 'bp_activity_set_just-me_scope_args', 'bboss_remove_activity_comments_override', 11, 2 );
function bboss_remove_activity_comments_override( $retval = array(), $filter = array() ){
    //this happens only only on user profiles,
    //so ideally this if condition should not be commented out.
    //But in this particular case, apparantely, this is happening on site-wide activity stream too,
    //so this if contidiont should be commented out
    //if( bp_displayed_user_id() ){
        $retval['override']['display_comments'] = 'threaded';
    //}
    
    return $retval;
}