Hello @Andrew_Rocker,
Glad to hear that rebooting the NAS has resolved the issue. As for optimizing your setup, I would make sure that you follow our Networking Best Practices Guide, but since everything is already connected via Ethernet you have most of that already set up properly.
Another great feature of Roon is our DSP Engine which you can use to tweak the audio to your liking using Parametric Equalizer, Sample Rate Conversion and a few other built-in features.
If the issue occurs again with the static, please let me know and if you can trace it back to Sample Rate switching then it may be a good idea to add a slight Re-sync Delay (listed towards the end of the KB article).
Hope this helps but do let me know if you have any other questions.
Thanks,
Noris