Steps to reproduce:

1. Download and import attached project. (Nestedsubemitters.zip)
2. Open scene: test2
3. Simulate particle system in the editor. Inspect particle system.
4. Press play. Inspect particle system.

Expected result: No difference is visible when doing steps 3-4.
Actual result: When simulating in editor, third sub-emitter in hierarchy does not burst its particles (emmision by time does not seem to have this particular problem). When played everything works fine.

Reproduced on: 5.4.0b21, 5.3.5p1, 5.2.5f1