Hey hey 
We have encountered the some weird behaviour in the particle systems we usually set up. When playing a particle system, which uses a texture for its particles, in the first frame of playing it, the texture is scaled up to span across the whole screen. It looks like a short flickering, after which the particle system behaves normal. It also only happens the first time the particle system is played. If we stop and reset it, the next time we play it it’s fine.
We finally managed to reproduce it properly in this project Reproduction Project. We added a script that starts the particle system during initialization, and added a short timeout, that pauses, stops and resets it during the next frame. Now we can clearly see that the particles are huge.
We know some settings that have an impact on this. Setting the particles texture to be preloaded seems to fix the issue, but in our games we tend to load most assets when needed. Also setting the sort order to “None” seems to resolve this issue as well.
Can you give us some insight, why these combination of settings are problematic? Is it a missuse of the component on our end, or did we find a bug?
Thanks
Alex