Warning - Modern Pages on Existing (None Microsoft Teams) SharePoint sites - Lots of things broken

Hi all,

Just an update on the misleading Site permissions side menu issue.  I logged a ticket with Microsoft support essentially turning this one away:

"We received the rejection from Microsoft product team on this ticket. They refused to change the permission behavior on the site page. Their original intention of the design on those groups [Owner/Member/Visitor] should have corresponding permissions [Full control/Edit/Read]. They don’t want the customer to change those groups’ permissions. Since those groups are created by SharePoint online system automatically, the product team hope the customer can use those groups normative as they hope."

I'm going to get back them about this one because I don't think the potential seriousness of this one has been thought about nor just how widespread this is.

Some more details regarding this one:

The issue occurs on all SharePoint sites (expect those automatically created via Microsoft Teams).  As a site owner I am able to click the settings cog in the top right and then Site Permissions.  This option is available from all “modern” style pages and apps in SharePoint, including modern pages, document librarys and the Site Contents page.  The information displayed here is not representative of the permission groups and levels available on the site, unless you have made absolutely no changes to the default groups and levels applied to those groups.  Which isn’t the case on any of our sites (200+) and I imagine the case in many SharePoint sites out there in the world.

What looks like a permissions level you are applying against a user is in fact some kind of default name given to the group, which we can’t change.  For example, on my test site there’s a Permissions group called “New Team Site Visitors” no matter if I give this group read, contribute or alarmingly full control, the drop down still displays read and when I choose to give someone the Read permissions they are put into the “New Team Site Visitors” group granting them whatever permissions level that is assigned to that group.

It is clear this new Site Permissions nenu bar option has been designed to work exclusively with SharePoint sites created through Microsoft Teams.  It definitely shouldn’t have been rolled out worldwide.  This site permissions option is the most obvious place to go to for owners to modify permissions and therefore this is going to cause potentially serious consequences.