Prevent Membership 2 Pro from taking over the "Add new" button on "My Sites" page on Multisite;

do-not-override-add-new-button-membership.php

<?php

// use this code as MU Plugin

function wpmu_dont_override_add_new_site_dash_button() {
	if (is_user_logged_in() AND is_admin()) 
		return network_site_url() . 'wp-signup.php';
}
add_action('wp_signup_location','wpmu_dont_override_add_new_site_dash_button',1000);