Force log off a user from Windows 10 pc

Bitlocker will not prevent more than one user from logging in at the same time.  Sounds like fast user switching might be disabled in GPO. Check the following: Computer Configuration > Administrative Templates > System > Logon

CBB, your observations about bitlocker are wrong and also the reported behavior with logged on users "surviving" a restart. Please describe in detail what you do and what behavior you observe.

you may simply disable Fast User Switching. for the steps and screenshot for Windows 10 interface, please see below link.

https://www.technipages.com/windows-10-enable-or-disable-fast-user-switching

Ok the one user log in is probably a feature of another third party security software i am using, but the user being kept logged on is a feature of Windows 10. It can be turned off in Settings -> Accounts -> Sign in Options. My issue is that i cannot log in. I am stuck at the log in screen and the only user being offered to enter their password is unavailable. Is it possible to force log off that user? Maybe through recovery/ command prompt?

My guess is this computer is not domain joined and only has one user account? If the computer has bitlocker enabled and you don't have the recovery key you don't have many options here other than to reinstall windows from scratch.

No the computer is not joined to a domain. It has several users but is only allowing that last signed in user to log back in. I have already passed the bitlocker authentication. It is the Windows log in that i am stuck at.