Information
Windows Server 2019 must prevent PKU2U authentication using online identities.
GROUP ID:V-205918
RULE ID:SV-205918r991589
PKU2U is a peer-to-peer authentication protocol. This setting prevents online identities from authenticating to domain-joined systems. Authentication will be centrally managed with Windows user accounts.
Solution
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> 'Network security: Allow PKU2U authentication requests to this computer to use online identities' to 'Disabled'.