Cannot shut down my book duo from power button

My book duo 24TB, has a slim power button in the back.
In the user’s manual, it says “Press Once, System will stop all services, clear cache and shut down gracefully”.
But when I press it once, the driver disconnects from Windows, but the HDDs are still running, then I have no way to stop it unless I unplug the USB cable, which is not really “gracefully”.
Of course, I can eject the driver from Windows Safely Remove Hardware icon, but the driver will auto-start with the PC boot-up.
I wish the power button is a real ON and OFF switch.

Hi @Maxmillian,

Have you opened a Support Case? If not opened, for more information, please contact the WD Technical Support team for the best assistance and troubleshooting:
https://support-en.wd.com/app/ask