There are several use cases when user roles are not synchronised between Azure AD and MS Teams, here are two examples with my expectations. Please let me know if they are correct or not, and if not - could I get the link to documentation with description of groups roles in Azure AD and MS Teams? Thanks.
Case 1
As User1 create new Team1 via MS Teams
In MS Teams: add User2 to Team1 and make them Owner
In Azure portal: go to Azure AD -> Groups -> Team1, check Owners and Members tabs << both users are listed in both lists as expected
In Azure portal: remove User1 from Owners list only
Actual result: User1 is removed from Owners and remains in Members in Azure as expected, but the team disappeared for the user in MS Teams
Expected result: I would expect for User1 to have access to the team as a Member
Case 2
As User1 create new Team1 via MS Teams
In Azure portal: go to Azure AD -> Grpups -> Team1, check Members and Owners tabs << User1 is listed under both of them and this looks to be correct
In Azure portal: add User2 to Owners list only << User2 is added to Owners list as expected, the user is also displayed as Owner in MS Teams
In MS Teams: change User2 role from Owner to Member
Actual result: User2 role has changed to Member in MS Teams, User2 is removed from Owners list in Azure and this looks expected. But User2 is not shown in Members in Azure as well.
Expected result: User2 should be added to Members in Azure portal
Regards,
Tanya