Does anyone know anything about fishhooks in Windows 10 and network drives?

I've just upgraded from Win8.1 to 10, and cannot map a WD My Cloud NAS as a network drive. Any time I try to add the NAS (or even browse to it from File Explorer) I just get an error message that it cannot be found. However I can ping it using its local address (192.168.1.20) or its hostname (wd.h) fine, and access its webpage from a browser. It also shows up fine using a WD windows app, just not in File Explorer.

I managed to get it mapped once using a WD setup utility, but as soon as I browsed away from that drive it disappeared.

I've checked SMB is installed (it is), as well as all the other obvious file and network sharing options.

The fact I was able to map it as a drive once (and ping it fine) makes me think it is some kind of bug.

Any suggestions?

I have tried Google and the Microsoft forums, but got frustrated at the prevalence of "Dear Friend. Please run the troubleshooter..." responses. There was also an issue about logging on with a PIN in one of the preview builds, but that seems to have been resolved.