understand how are users getting added to a group

[Ask_Ak]

Hello we have a group with name as <domainname>@<domainname>.com. Every new user that is onboarded gets added to the group as automatically get access to the team associated with that group. The membership type is "Assigned" and it's source is "Cloud". I am trying to figure out how are users getting added to this group. We do not add new employees to this group but they still get access to it. Unlicensed users and external users are not in this group.

[#2]

Is this perhaps an org-wide team? Even though membership is managed automatically for such, it will show membership type "assigned". In any case, you can check the audit logs for more detail.

[#3]

Thank you for your response.

Yes, it is an org-wide team. I checked logs and it says that initiated by actor is User-Agent
"SkypeSpaces/1.0a$*+" and Display name "MS Teams Services"

I tried to clean some users from the group but this service is trying to add them back but it fails.

1. I am trying to figure out, why is causing the users to be added to this group? Every new user we add gets access to this team including the non user identities such as conference rooms etc. Any recommendation on how can that be prevented from happening?

2. Also, why is it trying to re-add the users to the group that I have deleted from the Teams.

[#4]

My advice here would be to not use an org-wide team, they continue to have issues. Especially if you want a tighter control, org-wide teams are not a suitable solution.