Issue #3272985: RSS Feed header reverts to text/html when cached

core/modules/views/src/Plugin/views/display/Feed.php

@@ -29,6 +29,8 @@
  */
 class Feed extends PathPluginBase implements ResponseDisplayPluginInterface {
 
+  use ResponseDisplayPluginTrait;
+
   /**
    * Whether the display allows the use of AJAX or not.
    *
@@ -116,6 +118,9 @@ public static function buildResponse($view_id, $display_id, array $args = []) {
     $cache_metadata = CacheableMetadata::createFromRenderArray($build);
     $response->addCacheableDependency($cache_metadata);
 
+    // Allow the style plugins to alter the response.
+    static::alterResponse($response, $view_id, $display_id);
+
     return $response;
   }