In rare occasions, tests have reached their configured duration but keep on running. What may cause this?
The duration on the Summary Report actually reflects the configured duration of the test. What happened is that the test ended but somehow (one or few of) the load generators did not manage to notify the Blazemeter backend that the test had ended. In such case Blazemeter ends the test several minutes later (up to 1 hour) when it recognized that no test data comes in anymore for an extended period of time.
The test did run well and the metrics reflect the true configuration of the test. Only the End Time of the Summary report may be later than expected.