C7000v2 USB Storage Share Access Fails several minutes after reboot

I have a Western Digital 2TB My Passport Ultra USB 3.0 connected to my C7000v2 Cable-Modem Router.

I can successfully setup and access the folders as configured in the "available network folders" portion of the Advanced Settings under the USB Storage portion of the Advanced tab of the web based configuration interface.

Unfortunately, less than 10 minutes later, with no changes to the system, drive or router, I lose network access to the USB drive shares that were configured.

However if I log back into the router configuration page, I can still edit and add other network share items; so the USB drive is still alive and hasn't seemingly gone to sleep.

All when trying to access the share via \\Readyshare\(sharename)

(in the image below I have LocalNAS as my Readyshare root name fwiw)

Upon trying to access the share via the \\ReadyShare.routerlogin.net\(sharename) it starts to ask me for login credentials even though I have no password access setup for ANY of the shares.

The drive compatiblity page has several of the WD My Passport variants shown, so I believe that its not an incompatible drive.