I have been having a big issue with the free desktop version of teams for around a month now.
Originally I was able to sign into the desktop app and it would automatically sign me in everytime I turned the computer which was fine.
Recently however when I try to sign in it sends a verification code to my email, I then input the verification code and then password. I then get this error "You don't have access to this org in Teams. Select another org, or contact your admin for more details."
The very odd time it would behave normally and ask for an email and password and sign in normally, no issues at all.
I have no idea why it is behaving like this, the web version works fine and it was working for months without this issue.
@az123330 It sounds as if you have been invited to another org. as a guest and is still trying to connect to that org. / has not changed the tenant setting (top right corner). Try signing out from the desktop client (also top right corner) and back in again to see if it makes any difference.
There's also the 'Teams reset solution'. Meaning complete deletion of the Teams cache. Go to start and type %appdata%\Microsoft\Teams (delete all content in the Teams folder).
If on a Mac ~/Library/Application Support/Microsoft/Teams