Hello 이호진2
We understand it can be incredibly annoying to be unable to log in properly, especially when two accounts are linked, but only one works. It seems like the issue might be related to either Teams settings, a caching problem, multiple account conflicts.
Given that there are several factors to consider like Account Authentication Issues, Corrupted Teams Cache, Outdated Teams Version and Local System Conflicts, we need more information on the following to get a full picture of the issue and better assist you.
- Are the accounts that fail to sign in work or school accounts, or personal (outlook.com) accounts?
- Have you tried clearing the cache (Clear Teams cache) to see if it resolves the issue?
- Are you able to log in with these accounts on other devices or apps (we need this information to narrow down the issue)?
- Can you please confirm if the issue persists after reinstalling MS Teams?
Kindly let me know your responses to the above questions, and feel free to share any other details you think might help us resolve the issue. I look forward to your reply and am here to assist further. Please understand that our initial response may not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.
Thanks for your valuable time and cooperation.
Sincerely,
Bertrand | Microsoft Community Moderator