I have some that separate on my face too. It seems like when I use my foundation brush and not my beauty blender it does it more. Not sure why though?
I think sometimes it is just that it's not a fit for my skin type. I can't figure it out either! So frustrating.
Mix the Kevin Aucoin with moisturizer. I had a rep do my makeup and he mixed it for foundation and used it straight for a concealer. Game Changer.