Particles not renderering on transparent background



i have been trying to use the particle system on a transparent background however they do not seem to render properly.

based on formula in the user manual here

Blending Mode Alpha: Prgb x Pa + Drgb x (1 - Pa)

i’m assuming that the particle system isn’t using the alpha of the canvas.
hence the particles are technically drawing, but the alpha remains 0

or im doing something wrong here?

Thanks in advance!