Change views exposed filter value only on page reload
Just added a video link to show you : imgur.com/EmVha6e


You just need to add a conditional to check if it's not ajax

   $request = \Drupal::request();
   $is_ajax = $request-&gt;isXmlHttpRequest();
   if (!$is_ajax) {
     // code that sets the filter initial value
   }


Credit: How can I detect AJAX request inside Drupal?