Add maintains login in mixed env spec

qa/qa/runtime/browser.rb

@@ -237,6 +237,8 @@ module QA
           else
             browser.manage.delete_cookie("gitlab_canary")
           end
+
+          browser.navigate.refresh
         end
 
         ##

qa/qa/specs/features/browser_ui/1_manage/login/maintain_log_in_mixed_env_spec.rb

+# frozen_string_literal: true
+
+module QA
+  RSpec.describe 'Manage', :mixed_env, :smoke, only: { subdomain: :staging } do
+    describe 'basic user' do
+      it 'remains logged in when redirected from canary to non-canary node', testcase: 'https://gitlab.com/gitlab-org/quality/testcases/-/quality/test_cases/2251' do
+        Runtime::Browser.visit(:gitlab, Page::Main::Login)
+
+        Support::Retrier.retry_until(sleep_interval: 0.5) do
+          Page::Main::Login.perform(&:can_sign_in?)
+        end
+
+        Runtime::Browser::Session.target_canary(true)
+        Flow::Login.sign_in
+
+        verify_session_on_canary(true)
+
+        Runtime::Browser::Session.target_canary(false)
+
+        verify_session_on_canary(false)
+
+        Support::Retrier.retry_until(sleep_interval: 0.5) do
+          Page::Main::Menu.perform(&:sign_out)
+
+          Page::Main::Login.perform(&:can_sign_in?)
+        end
+      end
+
+      def verify_session_on_canary(enable_canary)
+        Page::Main::Menu.perform do |menu|
+          aggregate_failures 'testing session log in' do
+            expect(menu.canary?).to be(enable_canary)
+            expect(menu).to have_personal_area
+          end
+        end
+      end
+    end
+  end
+end