The Portrait Lighting features is still in beta, but just so you know that it quite quirky. I've seen some tests done by CNET and the results where sometimes inaccurate; the algorithm had troubles applying Stage Light around the hair and shoulder area of the subject.
I recommend watching that part in the videos shot by CNET. Jump to minute 1:30 and you can see what I am talking about. The photographer show the image in Portrait mode setting the lighting effect to Stage Light. Maybe in Studio Light Mono it would be less visible because it would be gray rather than pink-ish. You can clearly see that the algorithm still needs some more adjustments and optimizations.
This might be corrected in the final version, but as for now you can expect those type of results.