New albums added to qnap network server not found on nd5xs

Which upnp server software are you running on the qnap?

QNAP server running QTS 51.2.2533
Thanks for your reply

Yes, but what UPnP server software are your running on the QNap? Minim? AssetUPnP?

That looks like the QNAP operating system version you are running. Do you mean that you are running the bundled UPnP media server for your music files? Not that this should matter - any proper UPnP server should work, and if it’s only some new albums that are not showing, it may be that this server needs to be made to re-scan your music folder to incorporate them.
What is the origin of the files, and do you know that they have metadata that the server can read?

Yes it is the one that came with the QNAP which has been working ok with the nx5ds. The files are ok on the QNAP and I can play them ok on other systems using UPnP. It seems that the nx5ds is not updating to include the new files