It is not working for me either. I just did an upgrade to 23.0.0 in the hopes that this issue would be fixed. I can select a subject easily. I've tried to go into refine via a number of different clicks (paths) because I read that some people had success with previous bugs by getting into the refine edge in an alternate way.
The refine edge brush tool no longer highlights where I am drawing as I follow the edge of the hair, for example. Neither the + brush or the - brush appear to do any refining. When I click "okay", the results are very choppy and pixelated - not at all a smart selection. The smart radius box is checked. Clicking the "refine hair" button yields terrible results. The resulting edge is very choppy. See the attached screenshot after clicking "refine hair" and then "Okay" to show the results of refining.