only in patch2:
unchanged:
--- a/core/modules/views/src/Plugin/views/argument/StringArgument.php
+++ b/core/modules/views/src/Plugin/views/argument/StringArgument.php
@@ -317,7 +317,7 @@ function title() {
    * Override for specific title lookups.
    */
   public function titleQuery() {
-    return array_map('\Drupal\Component\Utility\SafeMarkup::checkPlain', array_combine($this->value, $this->value));
+    return array_combine($this->value, $this->value);
   }
 
   public function summaryName($data) {