some events are missing time related infomration

Some events have time related infomration set to null (firstTimestamp, lastTimestamp, eventTime)

cluster-logging.v5.8.0

100% 

    1.Stop one of the masters
    2.Start the master
    3.Wait untill the ENV stabilizes
    4. oc get events -A | grep unknown     

oc get events -A | grep unknow
default                                      <unknown>   Normal    TerminationStart                             namespace/kube-system                                                            Received signal to terminate, becoming unready, but keeping serving
default                                      <unknown>   Normal    TerminationPreShutdownHooksFinished          namespace/kube-system                                                            All pre-shutdown hooks have been finished
default                                      <unknown>   Normal    TerminationMinimalShutdownDurationFinished   namespace/kube-system                                                            The minimal shutdown duration of 0s finished
....

    All time related information is set correctly

   This causes issues with external monitoring systems. Events with no timestamp will never show or push other events from the view depending on the sorting order of the timestamp. The operator of the environment has then trouble to see what is happening there.