NSA325 Shares intermittently becoming invisible to Windows

I have a CIFS share on my NSA325 v1 that is dedicated to writing backups from my Windows notebook.  From time to time my backup software (Acronis True Image 2020) fails with error messages reporting that the target share is no longer available.  Rebooting the NSA325 usually fixes this, but I would prefer that it didn't happen at all.  When it does happen, the Acronis software starts referring to the target folder path using a weird string of characters that seems to include the MAC address of the NSA325 as part of the path, and it takes some trouble to persuade it back to finding the share using the \\[computername]\[sharename]\[folder path] syntax.

It is also the case that, when this does happen, all shares on the NSA325 show as "inaccessible" within Windows File Explorer, where they are mapped as drives, so I don't think this is simply a problem with Acronis True Image. 

Can anyone suggest a strategy to diagnose and fix this issue?  To start with, I'd like to know whether the issue is more likely to reside within the NSA325 or, alternatively, within Windows.


#NAS_Dec_2019