If you can’t login to a domain/local account after upgrading to Windows 10 Version 2004, then this post might help you to resolve the issue.
Unable To Log On To A Domain Or Local Account On Windows 10 Version 2004
Problem Symptoms
After upgrading to the May 10 update for Windows 10 Pro build 2004 on computers on a domain network, you may face issues and not able to log on to a user account, whether an authenticated domain or local account outside the domain network, such as at home, you cannot log on to the user account remains on the welcome screen, if you turn off the Internet connection before logging in, the profile will log in immediately.
Before upgrading to Version 2004, the login always worked outside the domain network, with the firewall in the OS categorizing the connection as a public network. So you agreed that issue is with this update, even though there is no mention of it on the Internet, so you hoped that perhaps the next cumulative update would solve this problem, but still after a recently released security update, the DNS client service will cause 100% CPU usage immediately after logging in. When you disable this service again in the registry, after a restart you log in to the domain network, but outside the domain again impossible, only a steady state on the welcome screen, probably with 100% CPU usage, as the fan on the CPU cooler is running at full speed. With the work account, you find that this problem occurs with a large number of clients, and the ability to come back before installing this update is no longer realistic. After trying many things to fix, the solution mentioned below did the trick.
Resolution
1. Press Windows + R, type sysdm.cpl and click OK.
2. In the Computer Name tab, click Change.
3. In Computer Name/Domain Changes window, switch the machine to Workgroup and type WORKGROUP. Click OK.
4. Restart the machine.
5. After restarting see if the problem persists.
6. If issue doesn’t occurs, rejoin your system to domain.
7. Else, make a clean install of Windows 10 Version 2004.