I made it. Sorry for the spamming 😉 But I suggest you update your blog post mentionned above with this code:
COPY CODE
add_action('bp_core_activated_user', 'kleo_add_member_activity');
function kleo_add_member_activity($user_id)
{
bp_update_user_last_activity( $user_id, bp_core_current_time() );
}
Best