Closing sequence does not restore state/stop playing montage if sequecne was saved during playback

Saving the sequence before closing it seems to keep a montage instance around even after the sequence is closed.

Repro steps in the attached project:

1. Open LS_TestCine_Master.
2. Scrub until the character moves forward toward the box.
3. Save the sequence (no other changes required).
4. Close sequencer.
5. Open LS_TestCine_Master.
6. Scrub and notice the character no longer reaches the box, and doesn't start in the right place