Hello, we got group writeback working however when I run the update-recipient "<group>" i get an error due to a couple of attribute values that Exchange 2010 doesn't understand.
msExchRecipientDisplayType 17
msExchRecipientTypeDetails 8796093022208
+ CategoryInfo : NotSpecified: (AD.CORP.LOCAL/G...ff-b273de87f6f6:ADObjectId) [Update-Recipient], DataValidationException
+ FullyQualifiedErrorId : 5D595360,Microsoft.Exchange.Management.RecipientTasks.UpdateRecipient
The property value you specified, "8796093022208", isn't defined in the Enum type "RecipientTypeDetails".
+ CategoryInfo : NotSpecified: (AD.CORP.LOCAL/G...ff-b273de87f6f6:ADObjectId) [Update-Recipient], DataValidationException
+ FullyQualifiedErrorId : 10FAD6F9,Microsoft.Exchange.Management.RecipientTasks.UpdateRecipient
If I manually blank out these value and run the cmdlet again, it works without error. The O365 group object is displayed as a group in the Exchange 2010 GAL. However, during the next dir sync, these values are put back and the object no longer "displays" as a group object in the GAL. The object entry is there in the GAL but there is no group icon nor is the name in bold (like other group objects). You can open the object and see the members and still use it for routing.
I read that you can prepare the schema for Exchange 2013 but I really don't want to go down that road. Is there a way to prevent those 2 attribute values from being sync'd back to OnPrem? I could probably write a powershell script that runs shortly after the dir sync to remove those values but preventing those attribute from writing back to on prem would be ideal.