There seems to be odd behavior for particles when coming in contact with collision surfaces. The particles continually move upward along the collision surface, in some cases increasing in velocity over time. It’s difficult to describe so here is a video. For easy reproduction, I am looking at the “Particle Sampler” demo scene.
Changing the particleMaterial’s “Cohesion” does help mitigate this effect but it has to be increased quite high to completely eliminate it.
Perhaps this is normal behavior and I am simply missing the correct controls to fix it?