I've had this problem before I upgraded to Photoshop CC 2017 as well as after. Once I close the app and launch it I notice that either all or a couple of my downloaded/created brush presets are missing.This happens most of the time but occasionally all of my brushes stay intact. I've been keeping folders full of new brushes and looking for a fix but no luck with that.
Is anyone else having this issue? Is there a fix?