This is one of the most mysterious problems I’ve encountered! Anyone who can provide input is more than welcome to ping me on Twitter or Teams, or help by entering some basic information in this form.
UPDATE September 6, 2022: Update the problem description as the Web sign-in setting is also causing problems using Cloud PC (Windows 365): “Another user is signed in. If you continue, they’ll be disconnected. Do you want to sign in anyway?”. See more below under “Problem #2”.
UPDATE July 6, 2022: A response from Microsoft leads to the root cause being Web sign-in being enabled, which is in preview (and has been for quite a few years) and is also unsupported. Still does not explain the extreme intermittent occurrence of the problem but at least a great indicator and something to validate.
UPDATE July 5, 2022: Added this form to gather and hopefully be able to get to the root cause. Also, I’ve gotten indications on a potential causes leading to the New user state, more below.
You restart your Windows 10 or Windows 11 device (Azure AD Joined + MEM/Intune enrolled) and after the restart, instead of displaying the last logged on user, the only account on the sign-in screen is an account named “New User”.
This happens extremely rarely, but I’ve seen it a few times. The “New User” comes from nowhere and if you click Switch user it just returns to the same view as below.
I have seen the problem a few times for multiple Windows 10 versions back to at least Windows 10 v1909, and on multiple devices from multiple vendors. Unfortunately I’ve seen it once on a Windows 11 device as well. The other day this problem hit a colleague of mine as well so it’s not just me :) .
Cloud PCs established as part of Windows 365, in Azure AD Joined mode, experience the sign-in message that Other user is already logged in, every time when logging in (and even after restart):
Another user is signed in. If you continue, they’ll be disconnected. Do you want to sign in anyway?
I’ve gotten reports (thanks to the community) with a response from Microsoft leads to the root cause being Web sign-in being enabled, which is in preview (and has been for quite a few years) and is also unsupported.
This is also true for the environments where I have seen this problem occur so this is the most likely cause of the “New user” phenomena causing Problem #1!
For Problem #2 this setting is confirmed to be the problem – as that problem was very easy to reproduce!
Disable Web sign-in!
The Web sign-in setting is really treacherous, causing a lof of head ache. I suppose this is the reason Microsoft is not recommending this setting.