Hi @Mervyn_Lim ---- Thank you for the post and sharing your feedback with us, very appreciated! I saw you had raised the same observations in this thread but in the interest of not having duplicate posts/keeping all of your information in single place I will be addressing your comment(s) “here”.
As mentioned in my post here there are some known limitation in the way NAS drives report changes to the OS that Roon is running under and we have some idea on how we maybe able to get around this behavior in the future but for now I would recommend considering the advice offered in John’s post above. Either using a “force rescan” on your watch folder(s) OR shortening the rescan intervals in Roon.
What is the exact model of Synology NAS you are working with and how do you have the settings configured on the device?
-Eric