Office 365 site collection admin not updated with O365 group owner

[Deleted]

Hi,

after a modern teamsite is provisioned the /mngsiteadmin.aspx page will show the newly created O365 group as a member. Due to that, I expected every member of the O365 group (Owner and Member) to be a site collection admin. Fortunately, this is no the case.

Members of the "Member" sub-group of the O365 group is not able to access /mngsiteadmin.aspx whereas members ofThe "Owner" sub-group are.

So I though I'd add a new user to "Owner" via the O365 portal -> Groups expecting this new user to gain site collection admin rights on the site collection. However, as with members of the "Member" sub-group, the user did not gain site collection admin rights (unable to access /mngsiteadmin.aspx).

So this makes me wonder: What's the logic behind and Office 365 group with its "Owner" & "Member" sub-groups in relation to the site collection administrator rights. 

Moreover, I find it very confusing that upon provisioning, the O365 group is added to the "Members of [siteTitle]" SharePoint security group although the O365 group itself has two sub-groups. 

What's your take on this?

Thanks for your input.

[#2 · Accepted solution]

You have to wait a bit for the owner to be granted site collection admin. There is a job or cache timeout that happens at some interval that adds them in the background. My guess is you tried to add them then immediately try to access this page. Owners are site collection admins, as members are members of the site.

[#3]

Thanks Christopher, I checked back today and now the user that was added can access /mngsiteadmin.aspx. It took way longer than I expected, though.

When you're in a modern teamsite and click on the cog wheel choosing "site permissions" (translating from another language), the menu will show three groups:

- site owners

- site members

- site visitors 

What's slightly confusing is that the O365 group is shown to be in "site owners" and "site members". However, when I go into /people.aspx the O365 group is only a member of the SharePoint security group "members of [siteTitle] but not "owners of [siteTitle].

Moreover it's confusing because if you put a user into "owners of [siteTitle]" he will get the "full control" permission level but is not a site collection admin. So essentially the "site owners" from the cog wheel shows users with different permission levels.

One more question. Is there're a PowerShell way to add users to either sub-group of the O365 group?

I'm able to get the members of each subgroup with "Get-UnifiedGroupLinks -LinkType" but how to I set them programatically?

Thanks.