Basic Niagara HangingParticulates glitch

Hello, I’m pretty new but I feel like there is something generally wrong with my install.
Here’s what I’ve done:

  1. I create a niagara system (HangingParticulates),
  2. change to GPUSim (i’ve tried both)
  3. remove sprite render
  4. add a mesh renderer (Cube)

When I hit play it looks as it probably should, but after about 2 seconds the blocks start to go opaque and flash in and out, once the 10 second sequence ends and it repeats, it is fine for another 2 seconds and then the same thing happens.

What am I doing wrong?

Here is a video of what’s happening: Particle flicker glitch - YouTube

UE4.26.2 (have also tried in UE5 and UE4.27.1)
AMD 3950X
96GB Ram
RTX 3080

I was just reading a thread with a similar issue. It’s marked as fixed, and at least has some comments to skim through for hints on your issue. It looks kind of similar.