MAGETWO-90053: Refreshing page deletes shipping address on guest checkout if module-persistent is enabled

Author: RuslanKostiv1

app/code/Magento/Persistent/Observer/CheckExpirePersistentQuoteObserver.php

@@ -127,8 +127,8 @@ public function execute(\Magento\Framework\Event\Observer $observer)
      */
     private function isRequestFromCheckoutPage(\Magento\Framework\App\RequestInterface $request): bool
     {
-        $requestUri = $request->getRequestUri();
-        $refererUri = $request->getServer('HTTP_REFERER');
+        $requestUri = (string)$request->getRequestUri();
+        $refererUri = (string)$request->getServer('HTTP_REFERER');
 
         /** @var bool $isCheckoutPage */
         $isCheckoutPage = (