I am seeing the same issue as described here:
WD Passport drives not spinning down when laptop in sleep mode.
THIS IS COMPLETELY UNACCEPTABLE, AS IT WILL LEAD TO PREMATURE FAILURE.
I want WD to confirm they are aware of this, apologise for this unacceptable bug, and link to a bug-tracker of some kind where I can trace this issue until it is resolved, which should be QUICKLY.