I have an AD integrated Distribution group that was part of my O365 migration. On-Prem exchange has been decommissioned. I also have an O365 shared mailbox. I am trying to add the shared mailbox to the distribution group but when I try from O365, I receive the error
"The action 'Update-DistributionGroupMember', 'BypassSecurityGroupManagerCheck,Identity,Members', can't be performed on the object 'Changes' because the object is being synchronized from your on-premises organization."
If I go into AD and try to add the shared mailbox to the distribution group, AD cannot find the shared mailbox. Any suggestions on how to make this work?