org.apache.beam.runners.flink.PortableTimersExecutionTest is very flakey 40/50 runs failed

I ran this test 50 on master and it failed about 40/50 runs. I have also seen this failing in jenkins presubmit.

build scan links from java presubmit
https://builds.apache.org/job/beam_PreCommit_Java_Commit/2654/

build scan links when I ran locally:

https://scans.gradle.com/s/hzu3bojfdbd5s
https://scans.gradle.com/s/txhyj6acebkko
https://scans.gradle.com/s/nhju5jthjbdds

org.junit.runners.model.TestTimedOutException: test timed out after 60000 milliseconds
at java.lang.ClassLoader.findBootstrapClass(Native Method)
at java.lang.ClassLoader.findBootstrapClassOrNull(ClassLoader.java:1015)
at java.lang.ClassLoader.loadClass(ClassLoader.java:413)
at java.lang.ClassLoader.loadClass(ClassLoader.java:411)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:339)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:13)
at org.junit.Assert.assertThat(Assert.java:956)
at org.junit.Assert.assertThat(Assert.java:923)
at org.apache.beam.runners.flink.PortableTimersExecutionTest.testTimerExecution(PortableTimersExecutionTest.java:191)
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$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:298)
at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:292)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.lang.Thread.run(Thread.java:748)