My original and still-unresolved problem is/was sharing data from an external drive connected to a Zorin computer with a Windows computer, over my Wi-Fi network. This issue was covered in detail, in a previous post: Problems sharing external drives from Zorin computer to Windows computers
I thought the situation might be remedied by working with two Zorin computers, instead of involving a Windows machine. Sadly, the problem persists! I'm not able to share/network any data from an external drive, despite confirming ownership is set to me, and all sharing permissions are established, including permissions for "Others". Every such setting that works for a successful share of a Zorin INTERNAL-drive folder fails completely, for sharing EXTERNAL-drive folders. The two screenshots below indicate what happens, when attempting to access external-drive resources via the local network.
I'm really at a loss here, and I would appreciate any thoughts on getting the external drive to properly share as a networked resource.