I have found this bug report which suggests that Volumio (or its underlying engine) has problems with handling libraries of over 10k.
I have a similar (the same?) problem. I added/mounted NAS using webui and it worked (green tick). Initially it was visible in the library and I could browse (and play) some of the music (it was still indexing, so only a few folders were visible), but now, after it has finished loading everything, I don’t even see NAS in the library folder in webui (only usb, radio etc.). Any suggestions? Has there been any progress made on the 10k files limit? (I am confident that my collection is way beyond that).
Do you know if minidlna has the same problem? Maybe I should switch from Volumio to minidlna and just stream from bubbleupnp? Are there any other alternatives for Rasp Pi+?
Thank you for help!