@User-Suren1 

Some routers do not have enough power in the USB ports to power some of the USB drives. You may need to use a USB power adapter.

Some routers do not support multiple drives or multiple partitions. 

Not sure how good it works but consider an Ethernet to USB adapter to use as your NAS. If you get one, let us know how good it works.

  @ArcherC8 The HDD enclosure has its power source, so it doesn't consume any power from the router.

"Some routers do not support multiple drives or multiple partitions. " - what about my particular router (Archer BE11000 Pro)? Does it or does not support multiple partitions or HDD-s?

Even if it supports one partition, it detects the drive, but gets disconnected shortly after, which is a technical problem of the router. I would understand if it was an old obsolete model, but my router is a brand new model purchased a month ago.

How should I use Ethernet to USD adapter with the router? To connect HDD through one of the router's Ethernet ports?

Thank you.

  @User-Suren1 

I have not attached more than one USB drive to a router knowing what others have encountered. A router is not a NAS. 

I have read about Ethernet to USB adapters and considered getting one instead of using the USB port on the router. Sites like cablesadvisor. com/adapter/nas show it being used as Ethernet connected to router and the USB to USB drives but the actual product descritions do not show that. There were some small boxes that did go from Ethernet to USB called NAS adapters but I do not see any in current production. Then there is always the Pi solution or a true NAS.