function prevent_tag_sync() {

    remove_filter( 'wprus_action_data', array( wp_fusion()->integrations->{ 'wp-remote-users-sync' }, 'merge_contact_data' ), 10, 3 );
    remove_action( 'wpf_tags_applied', array( wp_fusion()->integrations->{ 'wp-remote-users-sync' }, 'tags_modified' ) );
    remove_action( 'wpf_tags_removed', array( wp_fusion()->integrations->{ 'wp-remote-users-sync' }, 'tags_modified' ) );

}

add_action( 'wp_fusion_init', 'prevent_tag_sync' );