Particles created from two different particle systems do not collide with each other

Hi, I am trying to simulate the collision of a honey-like liquid and a water-like liquid. I created two particle systems with each one assigned a pbd material, and used those particle systems to create two liquids. But the problem was that these two liquid did not collide with each other. Is there any way to enable the collision of two particle systems? Or if there is any way to use a single particle system to create particle sets with different pbd materials?
Thanks

I am having the same question! An answer would we really helpful!