Particles Collision Flickering

Morning Guys,

I am working on a personal project and I am facing a particle collision issue.

So When a particle (red dots) collide and freeze on the ground it’s flickering so badely.
I am not using a GPU particle system and I don’t want because I need to use a mask.
Do you guys have any idea how to fix that for instance Maybe there is a way to offset in Z a particle when it collide on the ground and stop ?

Cheers

???
no one have any idea ?