Particles disappearing, but not gone

I’m working on an asset project in 4.8.
I’m using Spawn Emitter at Location to spawn some particles, which need to last indefinitely until I manually destroy them.
When I use either Destroy or Deactivate, the particles properly disappear, but somehow seem to still be consuming resources. If I repeatedly spawn and destroy the particle emitter, the frame rate gradually starts to dip when looking in the area the particles previously existed. As if they were still being rendered in that spot, continually piling up rather than going away.

Does anyone know what could be causing this, and how to fix it? I’ve narrowed it down to know that the particle being spawned is definitely the cause. If I run every single other part of the code EXCEPT spawning the emitter, everything is fine.
I have the particle set to Kill on Deactivate and Kill on Completed.

Ha, yep, you’re right. I had a loop nearby, and accidentally hooked the emitter spawn inside it instead of after. So every time I spawned one emitter deliberately, several more were getting spawned at the world 0 location underground and never getting destroyed XD

Are you sure your particles don’t have a very long lifetime but alpha out early? Try typing show wireframe in the console and you can see the left over particles.