So, not sure, but I think I got out of your network that the NUC\ROCK is ethernet? It does not specifically say that, though.
You might try going to settings/library and giving Roon a few cores to work with for analysis? Especially if it is turned of or throttled?
I am not familiar with Sooloos but I found this post (not sure if it applies to you? look at the response about SooLoos storage devices?):
You might also want to fix the “missing Codecs” on your Rock install?
6. Installing Codecs and Setting Up For First Run
You must install the appropriate Codecs for ROCK to function properly. You can do this by following the instructions here or by visiting the web UI listed on the console of the machine, click on the “?” next to "Missing Codecs" and follow the instructions. Be sure to also confirm that ROCK is on the latest version. You can trigger ROCK to update by selecting Reinstall from the Web UI.