Windows 10 Why does the lock screen keep restarting?

Question

Windows

I have a Fujitsu U772 laptop. On it a few days ago there was an update from win7x64 to win10x64 using the system itself. A few days after the update, strange behavior started. When the lock screen appears (a screen with a username and a password field), the system starts constantly reloading this window (a window appeared.. a clear blue background appeared.. again this window.. again a background.. etc.). One cycle is about a second.
What could be the reason and how to fix it?

Answer 1

Some kind of addition such as face authorization or even an antivirus, in general, look at the logs (Windows log) or calculate by removing installed programs.