I've been pulling my hair out today trying to use surface comb and sinks in UE5.3.2.

I'm working off a Metahuman with Metahuman hair. Converted that to an Ornatrix groom. Added a SurfaceComb, then added some sinks. Adding a few sinks worked. Then I wanted to edit those sinks. As per the documentation, I deselected the Sink Editor tool, but then the problems already start: 

- Sinks cannot be selected. (The surfacecomb layer was selected in the stack and I can see the handles for the sinks, but I can't select any of them beyond the first click/selection) (Addendum: Alt+RMB lets me select another sink, but...)

- Sinks cannot be moved at all. Neither the root nor the tip can be moved or transformed in any way. Selecting a root or tip and then dragging on the transform manipulator does either nothing or locks up the mouse cursor in that fixed position. 

- after that first couple of sinks added, I saved the scene/project. Returning to it later, I now cannot add any new sinks either 90% of the time. If I restart the editor, then select the Surfacecomb and try to create a sink, it very rarely works, but usually doesn't. 

(That's besides multiple crashes per hour and general instability when using ornatrix on metahuman hair...so maybe that's connected)