Cloud PC (Windows 365): “Another user is signed in. If you continue, they’ll be disconnected. Do you want to sign in anyway?”

If you try to connect to a Cloud PC (Windows 365 device) you can see the below message:

“Another user is signed in. If you continue, they’ll be disconnected. Do you want to sign in anyway?”

The root cause

This happens if you have configured Web Sign-in CSP policy to be Enabled.

Resolution

Make sure that the Web Sign-in CSP is disabled or not being set at all to start with.