Modern authentication

[elaheh]

Hi, 

I s there any way to disable Modern Authentication in Teams to avoid of SSO on the computer with shared credentials, that is a single account that several people use on one computer?

[#2]

Hi, have you considered using device-based licensing or shared computer activation instead? Meaning users sign in using their own credentials and not sharing credentials as described above.

https://docs.microsoft.com/en-us/deployoffice/device-based-licensing
https://docs.microsoft.com/en-us/deployoffice/overview-shared-computer-activation

I'm not aware of any easy "fix" for your scenario but you can try using the reg key for disabling the prefill of the UPN and see if it makes any difference. That is not signing in automatically.

https://docs.microsoft.com/en-us/microsoftteams/troubleshoot/known-issues/teams-defaults-to-domain-j...

[#3]

If the shared account doesn't have a M365 account, then they should always be prompted.
Otherwise always use private browser sessions and make sure that you log out of M365 each time.
It's not optimal, but it is one of the corresponding issues with shared machines.