I recently bought brand new 8TB My Book external disc and I’m having same issues as other people on this forum with different sized drives. Drive goes to sleep and never wakes up properly. Can’t un-mount it, when I do force un-mount it no longer mounts back, unless I pull the plug or completely reboot the Mac. I tried energy settings in preferences, Ampthetamine utillity, different cables, directly to usb, connected via Anker usb hub. Nothing helps.
I’ve got Toshiba and Seagate drives connected and never had such issue, I carry a small 1TB Passport drive and don’t have this issue neither.
Any way to fix this WD?
Did you follow below article in this concern?