Scott Euser · Andrey Postnikov
--- a/core/modules/big_pipe/src/Render/BigPipe.php
+++ b/core/modules/big_pipe/src/Render/BigPipe.php
            $cumulative_assets->setAlreadyLoadedLibraries(explode(',', $ajax_response->getAttachments()['drupalSettings']['ajaxPageState']['libraries']));
          }
        }
+        // Handle enforced redirect responses.
+        // A typical use case where this might happen are forms using GET as
+        // #method that are build inside a lazy builder.
+        catch (EnforcedResponseException $e) {
+          $response = $e->getResponse();
+          if (!$response instanceof RedirectResponse) {
+            throw $e;
+          }
+
+          $ajax_response = new AjaxResponse();
+          $ajax_response->addCommand(new RedirectCommand($response->getTargetUrl()));