It does work, so there’s something not right. 
 

How are you doing it? From app or Pc? What happens? What error message do you get? 

And have you tried calling the support team?

I have a Synology NAS and it took a few steps plus I had to add Sonos as a User on my synology with it’s own password that would allow access to my music library on my NAS drive.

Once done it works well but navigating categories has been diminished in the new app with the loss of an A-Z slider.  

support team was able to fix the problem.

when adding my path info into the sonos App the examples listed “shared” between the path and the folder. (see screenshot)

the support team did not put that between and i worked. not sure why its listed like that in the example but it sure would have saved me some head ache.

Glad its up and now

Looking at that, it would indeed have helped if they used two very different paths in their examples, but they were shown as examples to show how you should give the path to your music. 
 

Glad all is now sorted.