I had mentioned in a previous post about the inability to self service groups.
Problem: on-premises distribution group is synced to a Microsoft Office 365 organization through Active Directory synchronization, migrated users who are owners of the distribution group can’t manage it in Microsoft Exchange Online
Solution: Use the Exchange Tools (But we no longer have exchange on prem?)
Solution: Use Active Directory Users and Computers
Solution: Dsquery.exe – Press the Windows Key and R to open the run box and past in the following:
Owners of the group should be able to make changes when needed.
Note: You will still need to wait for dirsync to complete.