In SharePoint admin center, Add/Remove Owner greyed out for SharePoint sites

Hi Binayoke82,

I had this issue as well. It seems the ability to modify M365 groups has been removed from SPO Admins in the SPO Admin Center or on the site itself. You need to be an owner of the M365 group to modify the group on the site and will not be able to do it from the SPO Admin Center regardless from my experience. The only caveat would be that if you are a global admin, you may be able to as someone else in this thread mentioned they were.

However, as a SharePoint Admin, per the Microsoft Docs quote below, you should have access to modify the groups. I believe you also should inherit access to the M365 Admin Center (https://admin.microsoft.com/), though I may only have it because I have Global Reader. If you can access the M365 Admin Center, you can search for the group associated with the site and modify it there. This worked for me to gain ownership of the M365 group.

"Users assigned the SharePoint Administrator role have access to the SharePoint admin center and can create and manage sites, designate site admins, manage sharing settings, and manage Microsoft 365 groups, including creating, deleting, and restoring groups, and changing group owners."

Link to article: https://learn.microsoft.com/en-us/sharepoint/sharepoint-admin-role

My guess is that Microsoft is trying to decouple the SPO Admin center from the M365 Admin Center, or perhaps it is just a persistent bug.

Binayoke82 

Even i face the same problem, what i could see is all Teams (Group backed) sites are having this issue.

Don't find any problem with Communication sites, anyhow communication site template, doesn't have this option (Owners and Members group) available in Admin center, it has only Site members, Site owners, Site Admins and Site Visitors group. 

Binayoke82 I just checked in our SharePoint tenant and I am able to add site owners from admin center without any issue: 

Try using Global tenant administrator account once (if you have it with you). Anyway, I think this is issue at Microsoft's end for your tenant.

So, I will suggest you to raise a support ticket with Microsoft directly and report this behavior. Follow, Get M365 Support - Online Support 

Please click Mark as Best Response & Like if my post helped you to solve your issue. This will help others to find the correct solution easily. It also closes the item. If the post was useful in other ways, please consider giving it Like.