Recently I purchased two WD Pro NAS harddrives, each with capacity of 18 Tb. They were purchased to install existing WD 6TB ones. After I installed both of them, one of them would not initiate and generate error (model WD181KFGX-3PCKWN0 aka WD181KFGX-68CKWN0 ). NAS is Synology, with the latest...