I'm trying out the beta API's for Microsoft Teams that exist within Microsoft Graph. I have noticed that my request always fails when requesting a token with resource uri "https://graph.microsoft.com/", but it works on other API endpoints like "https://graph.microsoft.com/v1.0/me". If we change the resource uri to "https://graph.microsoft.com" the call does work for Teams releated API's.
Is this expected behaviour from the Graph? Is it related to being in beta?