Acronis Backup and Recovery prevents HDD spindown

Hi,

I just tested Acronis Backup and Recovery. Everything works fine, except the HDD spindown of my Windows 2008 R2 software RAID 5.
The drives should spin down after 20 minutes of inactivity, but after installing the agent (without creating tasks or modifying configuration) this doesn't work any more.
When setting the waiting time to 1 minute in the Windows power options, the disks sleep for a short time and then wake up again.
I see this because the PC needs about 30 W more power.

Spindown has worked with Acronis True Image Echo Server like it should.

In this case it is useful for me to send the disks to sleep, because they are needed only a few times a week.

Is there a way to fix this problem?

Regards