ParticleSystem.Emit() not emitting in correct place when set to local

I have a weird problem with a particle system.
It is a muzzle flash that I call from code every time the player fires with system.emit(1);
The particle system is pretty standard:


The problem is that after updating from 2017.1 to 2017.2 the flashes don't spawn in the right place (they spawn where the particle system originally was instantiated, even though it has now moved).
Here is a video of the problem: https://video.twimg.com/tweet_video/DN9HOIoW0AALl17.mp4

If I change the Simulation Space to World then it emits in the correct place, however obviously it is then in world space and that isn't what I want.

If I change a different value like scaling mode, it sort of updates the position that it emits from, but as soon as you move it is incorrect again.

This is a bug, right?

 

OK, thank you.