DL Issue

Dear All,

I have Exchange 2010 in our environment, When I want to add any user to any DL group through powershell. It gives an error, but if we add through GUI it works for me. when I have all the required access, even with my colleague has the same issue.

Please find below error. 

You don't have sufficient permissions. This operation can only be performed by a manager of the group.
    + CategoryInfo          : NotSpecified: (:) [Add-DistributionGroupMember], OperationRequiresGroupManagerException
    + FullyQualifiedErrorId : 98DC2EE1,Microsoft.Exchange.Management.RecipientTasks.AddDistributionGroupMember