Okay so I just looked at my XPS (which has a fingerprint reader) and noticed some things I need you to tell me / try. Do you only have one account on the laptop and is it an MS account or local account? The option to remove the PIN as a sign in option is greyed out on my system. It is not on yours. There is an option if you scroll down in the window which you screenshotted. It says "For improved security, only allow Windows Hello sign-in for MS account on this device..." is it on or off? Also you can try removing your finger and readding it (let me know if this changes anything).
I have enabled the access via fingerprint from the control panel, and the system recognizes my finger, however when I login I only see the option to enter my PIN code. Even just laying the finger on the power button does nothing.  Thank you.
Enable fingerprint access on XPS 13 9380