Niagara Particles Lifespan are very different if Unreal is running at 120 fps than 30 fps

Hi, I noticed that in Niagara, if I setup my particles to have a lifespan of .01 seconds, the actual lifespan is wildly different if the engine is running at 120fps than at 30fps. I assumed Unreal was doing an internal conversion to address this. Does anyone know how to fix this?

Thanks a bunch!