How do you readjust lightroom's automatic masking?

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?