We used "Test Stream" to make sure all of our nurture program transition rules were correct, but we kept getting confusing results. We could see in the activity logs that our testers were moving backwards between streams. They would successfully go from Stream A to Stream B and then mysteriously move back to Stream A without any triggers whatsoever. Here is an example of just one of the many occurrences during our testing:
This didn't make sense to us at all. We scoured Marketo docs and forums and could not find any explanation for what was happening. But, we finally figured it out...
The issue was in the Test Stream window. We were making sure the transitions were occurring in the Activity Logs, but weren't refreshing the Test Stream window. Every time we clicked Run Cast it would still think we were in whatever the window indicated was our Current Stream.
Test Stream does not actually pay attention to the Activity Logs. You HAVE to refresh the test stream by clicking the white refresh icon to move forward!
After we realized this, our testing went smoothly. Just thought we'd share in case anyone else runs into the same problem.