How do you readjust lightroom's automatic masking?

[Alex25666891ruux]

Hello, I am editing a photo and I am using lightroom's new feature of masking. Was great until this one image I have is super annoying. It is just a picture of someone snowboarding and it does a terrible job. I tried removing some of the mask overlay but doesn't seem to work. Below is a reference, please someone assist me. There is nothing else around the person yet it highlights extra stuff. How do I edit this and make it only highlight the whole person?

[elie_dinur]

You edit the mask manually by selecting Add or Subtract or both and choosing the tool with which to do it.

[Rob_Cullen]

If you select the Tool used in the Masking panel (eg. Subject 1) (Not the 'Mask 1' layer) then you click on the [Subtract] button and you can choose a Brush that will remove areas that the AI selected in error.