If there is a device linked to your account that you do not recognize, and if you are unable to remove that device from your account, you can use these steps on the link below to force a sign out on all devices linked to your Microsoft account, then you would need to log back into your devices, and that device you do not recognize would be logged out automatically and no longer have access to your account.
remove sign in from my account
Des Bowers
20
Reputation points
I am trying to remove a suspicious signed in device from my account but it will not disappear.
I have reset my password and attempted to remove it but it is still there?
Windows for home | Windows 11 | Security and privacy
Answer accepted by question author
DaveM121
919.8K
Reputation points
Independent Advisor