My NAS started to hibernate, but not without some extra configuration steps. Thanks for a link. It is helpful. I would just suggest 2 changes, as extra hints:
1. "Sync logging may also be a factor preventing your NAS from sleeping. To disable logging, create a debug.txt file in the storage folder and type "0" in it."
It is not that obvious how and where to create debug.txt file, especially on NAS where you don't have a direct access to the system folders. Disabling "Enable debug logging" option helped me partially, preventing logging "Tracker requesting peers" every 5 minutes. So the NAS started to hibernate (minimum time to hibernate is 10min), but now was waking up every 20 minutes, due to "UPnP: Device error" logging.
2. Disabling "Use UPnP port mapping" prevented waking up every 20 minutes due to logging some "UPnP: Device error" in my network.
I think that these 4 options we mention here should have a default setting that allows the devices to hibernate "out of the box", not the other way. Advanced users can set them up as they need.
Thanks for a quick response. Good the problem is fixed now