Hi, ChuckSheketoff!
Thanks for reaching out to Microsoft Community and posting your concerns. We are sorry to learn that your F8 key is not working on your Surface Book 2 to take screenshots. Thanks for taking the time to let us know about this and allowing us to help you out. First, we need to check if your Fn key is on or not. Please make sure it is not on. After that, press the Windows key together with the F8 (Print Screen) key. Once done, check if the screenshot has been saved in your files.
Let us know how it goes.
Kind regards,
Janette_Z