Windows 11 Showing as Windows 10

[DanielKeeley]

If you run this on a windows 11 os, the nuget will say it is windows 10.

[siewers]

Windows 11 will not be reported through User-Agent strings.
You will need to switch to using User-Agent Client Hints as described here: https://learn.microsoft.com/en-us/microsoft-edge/web-platform/how-to-detect-win11

Basically, you need to send some response headers for the initial request, to ask the browser to start sending the client hints you need. After that, you can read those headers from the requests onward.