Some ripped cds will not play through, only 1 track at a time, and have to be individually selected.

Which UPnP software are you running on the Synology? Whenever I've had problems like this with various NAS drives, I've found installing MinimServer makes them work well with Naim's network products. I'm sure there are other UPnP packages able to work just as well with Naims, but MinimServer is the one I've used most.

Is it compilation albums this happens with or single artist albums?

Are you on latest versions of streamer and app?

Look at the metadata of an album that works and one that doesn't and see if there is an obvious difference. 

The Naim app can only pull what it see so the issue is most likely with the tagging (although dbP is unlikely to be the cause) or as Andrew suggested the streaming program on your NAS. 

Asset which is made by the dbP people would be my first port of call. 

SJB

Thanks for your responses.  I suspect it's the Synology - I haven't updated the s/w since I got it.  I have never quite gotten to grips with the operation of this as it was installed by my audio dealer, I think I need to talk to them.  

Do you have media monkey? You should browse at the metadata to ensure the following:

- each track have a unique track# from 01 till the last track.

- all tracks belongs to the same "album name"

- there should also be no sub folder within this folder containing the track itself. 

The Mac dbpoweramp was updated in Jan 2016 to v15.4, so might be worth updating that too if you had rip issues.

How long ago did you get the Synology?  there have been a LOT of minor upgrades and fixes in the last few years.

Updating the Synology's OS is highly recommended - and it's easy.  Connect your browser to the Synology's home page on your network, go to the "Control Panel" and select Update & Restore and click <Update Now>...   Then wait about 10 minutes for it to do it's work!

As this is the first time you've done an update, make sure your data backup is up to date before you start (you DO have a backup, don't you!).

I very much expect its not the Synology, irrespective of if you are using Synology's own Media Server or Minimserver (what one are you using ? )    However per Huge's post,  get the updates done.  I have mine set to update automatically & it sends me an e-mail when it does so & it does this over night so nothing is interrupted.  Also while you are in the Synology webpage,  go to Media Indexing & re-index the music share.  

I think you are saying all the tracks from the CD are loaded & are visible in Synology's File Station & whatever Mac call their version of Windows Explorer.  

What app are you using - iOS or Android?  Have you tried a reinstall of the app to get the latest version,  if not you need to do that as it might be your problem.   But also reading you first post,  you seem to be missing the right place to play from on the Naim app

- you have three dots at the top right corner & three dots alongside each track

- touch the top corner dots it will give you a pop-up screen "Play the current queue"  "Play" "Queue Next"  .....  etc....  

- touch the track dots & the pop-up shows "Play From This Track" "Play This Track" "Queue next"  ..... etc.    

It plays each as it says on the box.