QNAP had a HUGE security problem a couple of weeks ago. You may want to try running their MalWare Remover app on your QNAP NAS. Also I noticed that after doing a QNAP NAS firmware update recently I was unable to connect to my network share (NAS). I had to enter the admin username and password to get my network share NAS to connect to my Intel NUC running ROCK. Hope this helps!
delete the roon Sever folder in the sharefolder of Qnap (you may want to back it up first but I didn’t)
Reinstall the roon app, to the drive where the multimedia consol located.
Enable the audio devices
I got my back the roon connection, audio device and tidal albums and playlists, but lost all the playlists created in roon which I originally thought I had got it back.
I still don’t know what had gone wrong with roon or my Qnap and why the above could fix it. No harm to give it a try. Hope this works for you. Good luck!