Our company has a policy that locks my computer after 5 minutes. After upgrading to Windows 10 when moving my mouse (to wake up the screen) I see my lock screen image, I then click the mouse to remove the lock screen image to present the login screen.
It then presents me the login screen quickly before starting to load again, displaying the spinning circle for 5-20 seconds.
After waiting 5-20 seconds it display the login screen again and I'm able to log on as normal. This happens to a few other employees as well.
We performed In-place upgrade from SCCM.