Steps to reproduce:

1. Download and import attached project.
2. Load scene: main
3. Play the scene and wait one sec till particles start to appear.
4. Press play on GUI. (Particle system pauses for one sec.)
5. Press stop and play afterwards.

Expected result: After pressing stop and play, particles on the screen should not be paused.
Actual result: When played, all particles are paused for 1 sec.

Reproduced on: 5.4.0b21, 5.3.5p3, 5.2.4f1