AD Receiver alert "Cannot apply linked attributes for some objects" Attribute already exists (4280669)

Repeatedly receiving the following AD Receiver alert.

<AD Receiver> (30835) Collection <Collection_Name>: Cannot apply linked attributes for some objects(3):
Object: CN=User Name,OU=HQ Forrest,OU=Quest Collaboration Services Objects,OU=Office,DC=Company,DC=com
Attribute: directReports
Values:
CN=User Name,OU=Support,DC=Company,DC=com (00002081: AtrErr: DSID-030F10D6, #1:
        0: 00002081: DSID-030F10D6, problem 1006 (ATT_OR_VALUE_EXISTS), data 0, Att 15000a (manager)
Attribute already exists or the value has been assigned.[EIP: 0x0679EF9F,0x067B4BCE]).

Please contact support to investigate the cause of these alerts.