Media Server :: Recorded / Post Processed Stream Won't Play Until Restarted

I'm having a very frustrating problem with FMS. A stream recorded on the server-side won't play until I restart the server.

The user flow I'm currently working with is:

1. record webcam stream

2. close the stream

3. call FMS function to post process the stream

4. FMS joins the recorded webcam stream with two pre-recorded videos and stores as a new stream
 
Then, knowing the new stream name, I'm trying to play it. However, I'm always seeing its last frame and it doesn't play. Surprisingly, restarting the server and re-connecting to it helps, then I can play the stream.
 
So I wonder if (server-side):

var stream = Stream.get("streamName");
stream.record();
stream.play(...);
stream.play(...);
stream.play(...);