This issue may be caused by the improper RBAC permission, please run below command to double check:
Get-Mailbox Identity | FL RoleAssignmentPolicy
Get-RoleAssignmentPolicy Identiy | FL Name,AssignedRole
In Active Directory Users and Computers you will find a new container called Microsoft exchange Security Groups. If you locate the group called Exchange Organisation Administrators and add your user in to this group it should resolve it.