I was doing a tutorial that was using a subdivided cube as the emitter object. When combing out the hairs, the Sculpt Collision brush worked very well. However, on my custom object, a dog head (with UVs), the comb brush doesn’t work when Sculpt Collision is activated. And when it is off, it combs the hairs into the mesh where they disappear.
I have googled this and even found one unanswered thread here on the forum about this very problem…so I don’t expect there will be a solution.
I’m using what someone told me was the GN system, not the Particle system. I use Curves>Empty Hair and then going into Sculpt mode.