Remove smart quote filtering on post title via wptexturize

remove-wptexturize-filter.php

if ( ! function_exists( 'text-domain_remove_title_wptexturize' ) ) {
	/**
	 * Turn off WP default smart quote conversions in post title.
	 */

	function text-domain_remove_title_wptexturize() {
		remove_filter( 'the_title', 'wptexturize' );

	}

	add_action( 'init', 'text-domain_remove_title_wptexturize' );
}

WP Ref: https://developer.wordpress.org/reference/functions/wptexturize/.
Disable the whole shebang: https://developer.wordpress.org/reference/hooks/run_wptexturize/
add_filter('run_wptexturize', '__return_false');