Microsoft is investigating a new known issue causing enterprise domain controllers to experience Kerberos authentication problems after installing security updates to mitigate CVE-2020-17049. The issue only impacts Windows Servers, Windows 10 devices, and vulnerable applications in enterprise environments. Microsoft is working on a fix for this known issue and will provide an update with additional details as soon as more info is available. The server platforms impacted by this issue are listed in the table below, together with the cumulative updates causing domain controllers and read-only domain controllers.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-kerberos-authentication-breaks-due-to-security-updates/