This is goofy & I sure can't figure it out.

My router (TP-Link Archer C7) has two USB ports. I am using OS X 10.11.6.
If I put a USB thumb drive in either of the router's ports, I can go to Finder - Go- Connect To Server and type: smb:// This will mount the USB drive and Finder sees it as "sda1". If I put in a second one, Finder sees it as "sda2". They mount like an external drive. Each can be accessed as though they were directly in the computer's USB port. So far, so good. All is normal.

If I eject, for example sda1, and put in a 3rd drive in its place (or erase the one that was sda1 with Disk Utility and put it back in), Connect To Server and Finder show "sdb1" for the new drive (note the a in now a b) and the "sda1" is still present and accessible- even though it physically no longer exists.

One can read files that are on the non-existent sda1, put new files on it and drag files from it to the desktop- just as though it was a physical drive.

I tried erasing all the USB drives, re-bootng the router and the computer, but the mystery sda1 still exists if any drive at all is in the router's USB port. Finder only shows it as a Volume. (makes sense).

If I eject the mystery drive, Finder no longer shows the files that are on it.

I can clear the server list to make it leave the list, but I am wondering where the files that it shows are actually residing. It isnít a physical device and Finder nor Easy Find can find the documents if the sda1 is ejected.

And, just for fun, looking at the file information in Finder shows "Date Modified", "Date Created" as "Tomorrow 4:58am" Tomorrow?
(They were created "today" at 8:20pm.)
The time on the computer & router settings match.

Crazy Huh?

Thanks for your thoughts!