Forum Discussion
"Everyone except external users" switch from Visitors to Members on PUBLIC O365 Group sites
Martin-Coupal I believe I figured it out on our end! I have sites staged in Yammer that I set to 'Read' for 'Everyone Except External Users' and I kept finding that the permissions had reverted to 'Edit' for the 'Everyone Except External Users' group. Turns out that when someone Joins the Yammer group, that user becomes a Member and permissions break - resetting them to the default. With testing, I was able to replicate this behavior several times over.
Elizabeth Robinson On my side, there was no change in group membership (and the group was not used with yammer) but this is an interesting observation.
Martin-Coupal as I understand it the Yammer group is essentially an O365 group but the membership change is definitely what's happening on my end. We have it escalated with MS support now so I'll update with the resolution in case it helps with what's happening on your end.