External storage issue

> More than me!

   Perhaps, but, as I said, my actual experience with ReadySHARE
consists of some (not much) reading.

> So advice is to forget about using this as a network drive through the
> router?

   The way I look at is this:

   You "copied some files onto" the disk, which, I gather, is still
formatted with a NTFS file system, as supplied by Seagate.  I assume
that if you eject and disconnect the drive from the Mac, and then
reconnect it, those files are still seen by the Mac (Finder).

   Then you eject and disconnect that disk from the Mac, and attach it
to the router, which seems happy enough, but now those files which you
know must be on the disk are not visible?

   Unless there are some odd-ball permissions involved (which doesn't
seem very likely), then I'd say that the Paragon NTFS file-system

software is doing something on that disk which confuses the GNU/Linux
NTFS file-system software on the router.  At least one of them could
have a bug, and file-system bugs are not particularly desirable if you
expect a backup (Time Machine or other) to be useful.

   One more thing I'd want to test would be if you could actually do a
Time Machine restore operation using a backup from that
ReadySHARE-served NTFS file system.  In principle, the normal Mac OS can
read a NTFS file system (without the Paragon software, which might not
be available in the macOS restore/recovery environment), and it should
be able to do network access, too, so it could work, but I'd want to see
it work before I trusted it.  Which would be true of any backup system.
A write-only backup system always looks good when you don't need it, but
tends to disappoint when you do need it.

   Around here, I use an old Seagate NAS220 network storage gizmo for my
Time Machine backups.  I don't know what the actual on-disk file system
is in that thing, but I believe that it's some native GNU/Linux thing
like "ext3".  But the NAS box runs software which presents the data to
the network as an Apple File System volume.  (You can see the Time

Machine XXX.sparsebundle files using the Finder Go > Connect to
Server... > afp://nas220 [...], just like any normal Apple-shared
volume.  ("Get Info" says: Kind: Mac / Where: Network.)

   There's still software involved (as usual; it's hard to avoid), but
the actual underlying file system is an OS-native one, and the only
worry is the Apple File Protocol layer on the NAS box.  And it did
actually work for me recently, when the (original) disk in my MacBook
(13-inch, Aluminum, Late 2008) died.  So, network storage for Time
Machine backups has worked in the real world.  Whether ReadySHARE with a
NTFS disk works, I don't know.

   If all you care about are Time Machine backups, then you might also
consider formatting this disk with an Apple-native file system, instead
of its original, Windows-friendly NTFS.  You'd still need to worry about
the router's Apple-file-system software, but it'd be a different stack
of stuff from the NTFS stack.  I'd still test it, and realistic testing
is the best advice I have for any proposed backup scheme.