Hey baconsoda,
We’d be happy to help out. If your library isn’t seeing your music from a NAS, the first thing to do is make sure that you’re able to access the NAS through Finder. If Finder is seeing it then it should be online and communicating with your Mac without issue.
After doing so, then make sure you have the correct library location selected. For help doing so, check out: Change where your music files are stored on Mac - Apple Support
Once you’ve ensured the correct location on your NAS is selected, if you still have issues, since you mentioned wanting to “reset” the Music app, you could always create a new library altogether and delete the existing one afterward using these steps:
Create or choose a library
1. In the Music app on your Mac, choose Music > Quit Music.
2. Hold down the Option key while you reopen Music.
3. In the window that appears, do one of the following:
* Create a new library: Click Create Library.
* Choose a different library: Click Choose Library.
You can name your new library (the folder containing your Music content) whatever you like. For best results, if you create additional music libraries, don’t name the new libraries “Music” or “New Music.” Make sure each library has a unique name so you’ll know which is which.
Once the new library is done being built, you can delete the old library wherever it’s currently stored on your NAS.
We hope this helps out.
Take care!