Audio settings are
The watched folder on my NAS has new music on it but unless I force rescan I don’t see it in Roon.
As to my experience a rescan may take a while, depending on the amount of audio files in the folders and depending on the power/bandwidth of the server (which is a Synology NAS in my case). One of the two paths given in your screenshot looks like you have the flac files on a network drive (probably a Synology NAS, too) but you did not establish an SMB mount to a drive letter. Network paths in SMB are much more “costly” than SMB drive mounts because in the first case SMB protocol has to deal with much more security requests (these are not cached). This will slow down the directory traversal by order of magnitude.
I’d recommend to set a drive letter to the network path/volume and see what happens.
Yes it is a Synology NAS attached via CIFS. It has had 18 hours to update…
I’ll try using it mapped to a drive letter and see what happens.