media list empty on sharp radio
I installed serviio pro 2.2 on a macbook pro with Big Sur and it's currently in its evaluation period.
I am trying to serve audio content to be listened through a DR-1470 GR Sharp radio.
I've setup my library to the root of "Music" folder and the Serviio console shows there are 40k+ music files in the library, and that's ok.
when I access the media player on the Sharp radio, it lists a dozen (?) of Upnp Serviio items, but if I select any of them i get "empty" and there are no media files or folders.
it also lists a couple of Router Upnp items, but they too are completely empty.
The Serviio console shows a device connected from Sharp's radio IP; it is assigned the generic DLNA profile. I could not fine any clearly related profile in the profile list (tried Sharp aquos but nothing changed). The item has a green dot on its left, so I assume the connection is ok. [EDIT: the green dot stays there even after turning off the Sharp device]
I tried creating a user and assigned it to this device, but nothing changed.
I tried activating the Upnp feature on the router, but nothing changed.
the firewall of my mac is off.
I just can't figure what I should change to solve the issue. My research on the forum led me to several empty content related posts, but they were all referred to the Serviio MediaBrowser, or to a situation where the client device shows a list of folders, which are empty. In my case, I do not even see the folder structure of the library.
thank for any help
stefano