Simplest is check if you can play mp3/aac streams.
The Capodistria stream is aac, and this is the codec that can be missing from a synology NAS.
Check these two stations:
Radio Italia Anno 60 is just aac,
and Radio 105 Indie is just mp3. Are these both ok? Or just the mp3 one?
I realise I gave you the wrong link for Synology codec issues (which should only affect aac streams ) - this link and this one are more suitable.