Fix AD Group Name Sync
If you change the name of an AD Group SharePoint doesn't synchronise this change to the Site Collection. You have to manually delete the group in the Site Collection users list or with Powershell.
A good reference on this: https://blogs.technet.microsoft.com/marj/2015/11/20/how-does-renaming-an-active-directory-group-impact-user-access-people-picker-and-audience-targeting-in-sharepoint-2010/
Please fix this.
Kevin Still commented
@Kenneth, what PowerShell script are you referring to? I can't find a working one, I changed a bunch of group names and they are not updating in SP Online and its very annoying.
@Kenneth, the point is that you shouldn't have to perform a separate PowerShell operation to just to have SharePoint display the correct name!
SP should be referencing the group's sAMAccountName or CN and update it automatically when a sync occurs.
The same problem exists for users and has been around forever. It's high time this problem was fixed.
This can be fixed via PowerShell if people are having this issue. The "User Information List" is a hidden list that contains the names of all users and groups per site collection. Changing the title there will correct the user/groupname on that site collection.