I have faced a Similar Issue with Creating Teams which was Automated via SDS Sync. What I noticed was, when Team Owners whom I assigned created teams and it will work on the first time. But, for some it created a Duplicate Name
of the Sharepoint site of the teams, so please goto Your admin centre, sharepoint - Sharepoint Sites and check out, whether there are owner ship assigned. You can also check the Admin Centre User --> Group Setction. Check that particular Teams Group is duplicated.
The only thing, I did was to Delete the Sharepoint and Group Teams and created another via SDS Sync. May be in your case, you can add the owners in Sharepoint policies.
In conclusion: There is something weird about sharepoint sites creation for teams and sometimes, the owners don't get to be in the sharepoint site, all the it appears in the Group.
If you need further help, perhaps I can assist.
I did wait for microsoft support its been two weeks since I Open up a ticket, but no resolutions at all.