Workaround to remove BuddyPress registration overrides

mu-plugins-functions.php

<?php
/**
 * Put this file into the `wp-content/mu-plugins` directory.
 */

function restore_wp_registration_url() {
	return site_url( 'wp-login.php?action=register', 'login' );
}

function use_a_specific_wordpress_page() {
	$page_id = 1; // replace with your page ID.
	return get_permalink( $page_id );
}

function remove_bp_registration_overrides() {
	remove_filter( 'register_url', 'bp_get_signup_page' );
	remove_action( 'bp_init', 'bp_core_wpsignup_redirect' );
	
	// To restore the regular WP Registration URL, uncomment the following line.
	//add_filter( 'bp_get_signup_page', 'restore_wp_registration_url' );
	
	// To use a specific WordPress page, uncomment the following line.
	//add_filter( 'bp_get_signup_page', 'use_a_specific_wordpress_page' );
}
add_action( 'init', 'remove_bp_registration_overrides', 1 );