Hi Phil, Duo currently doesn’t support Windows Hello, though this is something we are working on for the future. We can’t share updates publicly in the community, but there is a feature request. For anyone reading, you can have your name added or request more information from your Account Executive or Customer Success Manager (if you have one) or the Duo Support team.
You may still be able to get it to work, as you’ve noted, despite the lack of official support. If others in the community have advice to offer you, I’d be interested to see.