HubRenderIT::changeModeAndState_modeAndStateAreKept is flaky

[mshabarov]

Portlet 1.0 HubRenderIT::changeModeAndState_modeAndStateAreKept test fails time to time without any reasonable cause within Validation with Flow 2.5:

java.lang.RuntimeException: changeModeAndState_modeAndStateAreKept[ANY_Chrome_](com.vaadin.flow.portal.rendermodes.HubRenderIT): run failed 2 times
	at com.vaadin.testbench.RetryRule$1.evaluate(RetryRule.java:69)
	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.apache.maven.surefire.junitcore.pc.Scheduler$1.run(Scheduler.java:393)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.openqa.selenium.StaleElementReferenceException: stale element reference: element is not attached to the page document
  (Session info: chrome=89.0.4389.82)
For documentation on this error, please visit: https://www.seleniumhq.org/exceptions/stale_element_reference.html
Build info: version: '3.141.59', revision: 'e82be7d358', time: '2018-11-14T08:17:03'
System info: host: 'ip-172-16-1-59.eu-west-1.compute.internal', ip: '172.16.1.59', os.name: 'Linux', os.arch: 'amd64', os.version: '4.14.123-111.109.amzn2.x86_64', java.version: '1.8.0_201'
Driver info: org.openqa.selenium.remote.RemoteWebDriver
Capabilities {acceptInsecureCerts: false, browserName: chrome, browserVersion: 89.0.4389.82, chrome: {chromedriverVersion: 89.0.4389.23 (61b08ee2c5002..., userDataDir: /tmp/.com.google.Chrome.S15jNy}, goog:chromeOptions: {debuggerAddress: localhost:38413}, javascriptEnabled: true, networkConnectionEnabled: false, pageLoadStrategy: normal, platform: LINUX, platformName: LINUX, proxy: Proxy(), setWindowRect: true, strictFileInteractability: false, timeouts: {implicit: 0, pageLoad: 300000, script: 30000}, unhandledPromptBehavior: dismiss and notify, webauthn:extension:largeBlob: true, webauthn:virtualAuthenticators: true, webdriver.remote.sessionid: 070d64aa502f016f7d1a6051138...}
Session ID: 070d64aa502f016f7d1a6051138a584a
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at org.openqa.selenium.remote.http.W3CHttpResponseCodec.createException(W3CHttpResponseCodec.java:187)
	at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:122)
	at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:49)
	at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:158)
	at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:552)
	at org.openqa.selenium.remote.RemoteWebDriver.executeScript(RemoteWebDriver.java:489)
	at com.vaadin.testbench.TestBenchDriverProxy.executeScript(TestBenchDriverProxy.java:187)
	at com.vaadin.testbench.TestBenchDriverProxy_$$_jvst1e7_0._d4executeScript(TestBenchDriverProxy_$$_jvst1e7_0.java)
	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.vaadin.testbench.DriverInvocationHandler.invoke(DriverInvocationHandler.java:51)
	at com.vaadin.testbench.TestBenchDriverProxy_$$_jvst1e7_0.executeScript(TestBenchDriverProxy_$$_jvst1e7_0.java)
	at com.vaadin.testbench.commands.TestBenchCommandExecutor.executeScript(TestBenchCommandExecutor.java:255)
	at com.vaadin.flow.portal.AbstractPlutoPortalTest.lambda$getShadowRoot$9(AbstractPlutoPortalTest.java:312)
	at org.openqa.selenium.support.ui.FluentWait.until(FluentWait.java:249)
	at com.vaadin.testbench.TestBenchTestCase.waitUntil(TestBenchTestCase.java:223)
	at com.vaadin.testbench.TestBenchTestCase.waitUntil(TestBenchTestCase.java:247)
	at com.vaadin.flow.portal.AbstractPlutoPortalTest.getShadowRoot(AbstractPlutoPortalTest.java:312)
	at com.vaadin.flow.portal.AbstractPlutoPortalTest.getPortletById(AbstractPlutoPortalTest.java:237)
	at com.vaadin.flow.portal.AbstractPlutoPortalTest.getFirstPortlet(AbstractPlutoPortalTest.java:248)
	at com.vaadin.flow.portal.rendermodes.HubRenderIT.changeModeAndState_modeAndStateAreKept(HubRenderIT.java:83)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at com.vaadin.testbench.parallel.ParallelRunner$TBMethod.invokeExplosively(ParallelRunner.java:494)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at com.vaadin.testbench.parallel.ParallelRunner$1.evaluate(ParallelRunner.java:468)
	at org.junit.rules.TestWatcher$1.evaluate(TestWatcher.java:55)
	at org.junit.rules.TestWatcher$1.evaluate(TestWatcher.java:55)
	at com.vaadin.testbench.RetryRule$1.evaluate(RetryRule.java:59)
	... 11 more
------- Stderr: -------
Mar 31, 2021 11:01:56 PM com.vaadin.testbench.parallel.SauceLabsIntegration setDesiredCapabilities
WARNING: Null or empty sauce.options given. Ignoring.
Mar 31, 2021 11:01:58 PM org.openqa.selenium.remote.ProtocolHandshake createSession
INFO: Detected dialect: W3C
Mar 31, 2021 11:02:04 PM com.vaadin.testbench.parallel.SauceLabsIntegration setDesiredCapabilities
WARNING: Null or empty sauce.options given. Ignoring.
Mar 31, 2021 11:02:07 PM org.openqa.selenium.remote.ProtocolHandshake createSession
INFO: Detected dialect: W3C

https://bender.vaadin.com/viewLog.html?buildId=221940&buildTypeId=Flow_Flow25_AddOns_FlowPortlet10