External HDD won't spin down even on idle

I looked around and found mixed answers.

I just install OSMC today and I have a problem where HDD won’t spin down even on idle, I use both OpenELEC and OSMC so I went to check again on OpenELEC and the HDD will spin down on OpenELEC but not on OSMC.

Is this a bug or did I miss something?

bump

You probably aren’t getting any feedback because this has been discussed already in several threads.