Does it ? Apparently not as you are complaining that it sounds harsh. So it looks like you are using some kind of back door to get Mosaic to play files via your network from your local storage without using the correct UPnP software. Please use:
https://minimserver.com/index.html
Be sure to choose the correct version for your computer as I understand that is your storage medium.
You also need to download MinimWatch 2 in order to configure the server software and to rescan the database if you add albums/tracks.
I would guess that this may be why you find network audio outside of Roon currently less than satisfactory. Case solved?