At least when it was released, IIS 10 supported HTTP/2, but did not support Kerberos, Negotiate or NTLM authentication over HTTP/2. https://docs.microsoft.com/

At least when it was released, IIS 10 supported HTTP/2, but did not support Kerberos, Negotiate or NTLM authentication over HTTP/2. https://docs.microsoft.com/en-us/iis/get-started/whats-new-in-iis-10/http2-on-iis https://docs.microsoft.com/en-us/iis/get-started/whats-new-i... I’m not sure that it’s a problem with HTTP/2 that Microsoft found no reason to implement Windows authentication for it.