Make all Ultimate Member User Profiles Private by Default.

um-force-private-profile.php

<?php
/**
* Ultimate member - Make all UM User Profile Private by Default.
* URL: https://wordpress.org/plugins/ultimate-member/
*/
add_filter( 'get_user_metadata', function( $profile_privacy, $object_id, $meta_key ) {
	if( $meta_key === 'profile_privacy' ) {
		$profile_privacy = 'Only me';
	}
	return $profile_privacy;
}, 30, 3 );