Yoast SEO - Redirection RegEx Rules Differ Across Languages with WPML

Overview of the issue

When using the Yoast SEO Pro plugin, RegEx redirect rules do not work in the same way across different languages. There is a different behavior for the default language and the second language.

For example, if you create a redirection rule like ^/en/faq/(.+)$ to /en/support/$1, it might not work as expected when trying to access it through http://example.com/en/faq/test/.

Workaround

Option 1

As a quick workaround you can create different rules.
Following the initial example:

• ^/faq/(.+)$ redirects to /support/$1
• ^faq/(.+)$ redirects to /en/support/$1

Option 2

 
Please, make sure of having a full backup of your site before proceeding.

• Open …/wp-content/plugins/wp-seo-multilingual/classes/class-wpml-wpseo-redirection.php file.
• Look for the line 34.
• Replace this code:

  foreach ( $redirections as $redirection ) {
      if ( $redirection['origin'] === $url || '/' . $redirection['origin'] === $url ) {
          return true;
      }
  }
  

• With:

  foreach ( $redirections as $redirection ) {
  				if($redirection['format'] == 'regex'){
  					// Ensure $url starts with /, if regex would need to check if string starts with this is needed.
  					if(strpos($url, '/', 0) !== 0){
  						$url = '/' . $url;
  					}
  					// Lets use ~ as a regex delimiter instead of /, as we are matching a URL.
  					preg_match('~' . $redirection['origin'] . '~', $url, $matches); 
  					if(count($matches) > 0){
  						return true;
  					}
  				} else if($redirection['origin'] === $url || '/' . $redirection['origin'] === $url){
  					return true;
  				}
  }