I can also replicate the same thing on a sphere, as you have demonstrated.
It seems that the issue could be scale and the rigging or morph poses. I noticed in fact, my sinks seem way off (even when dissabling the skinning of the mesh) and tiny. additionally the axis is flipped due to my import being at this axis, could it affect ornatrix?
I'm coming from iClone and know of no way of adjusting scale of mesh upon export or import. To counter this i tried scaling up the rig alone to 100, upon first attempting this I did in fact get desirable results with the surface comb however my sinks still exist offset and very small away from the mesh. Heres when it gets weird, i tried to repeat the process 3 times in replica scenes, failing to do so, the sink tool does not create any sinks when i attempt to create them, eventually I went back and repeated the attempt on the other files and for some reason it worked in two other test scenes. Seems like some sort of a bug to me.
I now cannot get it to work in my final scene as i had hoped and have multiple meshes to work on, hopefully you can shed some light on this problem?
Thanks
Heres some of the project files
https://drive.google.com/open?id=1UTltJvda3htNNpWdlXUqhQitLfhorBLK&authuser=studio%40ior50.com&usp=drive_fs
