PHP Warning: Undefined variable on PHP 8.1.28

Hey team, I am getting the following PHP Warning: Undefined variable on PHP 8.1.28:

PHP Warning:  Undefined variable $index in path-to-sitewp-content/plugins/diagnoseo/includes/class-diagnoseo-metatags.php on line 455
PHP Warning:  Undefined variable $index in path-to-sitewp-content/plugins/diagnoseo/includes/class-diagnoseo-metatags.php on line 456
PHP Warning:  Undefined variable $follow in path-to-sitewp-content/plugins/diagnoseo/includes/class-diagnoseo-metatags.php on line 457
PHP Warning:  Undefined variable $follow in path-to-sitewp-content/plugins/diagnoseo/includes/class-diagnoseo-metatags.php on line 458

While troubleshooting, I found out that the Diagnoseo_MetaTags::meta_robots() method was producing the PHP warnings due to the use of undefined variables $index and $follownot being set when none of the if or elseif conditions were met, leaving these variables undefined when they were later used to set values in the $robots array.

As a temporary fix to ensure that $index and $follow are always defined, they were initialized with default values at the beginning of the meta_robots method. Which I’ve added to fix the issue for me:

public function meta_robots( $robots ) {
    $index = 'noindex'; // Default value
    $follow = 'nofollow'; // Default value

I hope this helps, and please let me know if you need any clarification about the issue from my end.