I use Kanban Tool inside Teams - why are some of my users doubled?

The problem has an easy explanation, and a simple solution.

When using Kanban Tool with Microsoft Teams, your team members should create their Kanban Tool users for themselves by using the “Sign in with Microsoft” login button on the Kanban Tool tab. Doing that creates a user integrated with the person’s Microsoft Teams profile, and you will see an MS Teams badge next to those usernames on the account’s People page:

But, to allow for a collaboration with people outside of your organization, e.g., clients, contractors, consultants, etc., you can also invite a new member manually by typing in their email address. A member created in this way will not have an MS Teams badge on the user list, and will need to log in with a username/password combination rather than the Microsoft Teams Single-Sign-On button.

Therefore, if you go to your account’s People list and see two records for a given person - one with an MS Teams badge and one without, it means someone on your team has manually invited this person instead of waiting for them to join by clicking “Sign in with Microsoft”. The two records referring to the same person are completely separate users, and it is best to suspend one of them to minimize confusion. If the member in question is part of your Microsoft organization, please suspend the one that lacks the MS Teams badge, and kindly make sure they are aware of now having to log in with the Microsoft login button only.

After that, please take a moment to review your Kanban Tool boards’ share pages to make sure the no-longer-doubled team member is ticked (✔) for access to the boards they need.