Remove CPT permalink base

function bis_rewrite_cpt_permalinks( $post_link, $post, $leavename, $sample ) {
    if ( ! empty( $post->post_type ) && in_array( $post->post_type, array( 'video_skrn', 'episodes_skrn' ) ) ) {
        if ( $leavename ) {
            $post_link = home_url( "%{$post->post_type}%" );
        } else {
            $post_link = home_url( $post->post_name );
        }

        $post_link = user_trailingslashit( $post_link );
    }

    return $post_link;
}
add_filter( 'post_type_link', 'bis_rewrite_cpt_permalinks', 10, 4 );

function bis_parse_cpt_permalinks( $query ) {
    if ( ! $query->is_main_query() || 2 != count( $query->query ) || ! isset( $query->query['page'] ) ) {
        return;
    }

    if ( ! empty( $query->query['name'] ) ) {
        $query->set( 'post_type', array( 'post', 'page', 'video_skrn', 'episodes_skrn' ) );
    }
}
add_action( 'pre_get_posts', 'bis_parse_cpt_permalinks' );