Sun May 08, 2016 4:06 pm by Geth
Though I have a QNAP NAS, I've just discovered something related to this.
I had a media folder set up in Serviio which was a symlinked one.
If a new media file was created/deleted somewhere deeper in the folder hierarchy, Serviio was notified about the change.
If the change was in the root of the symlinked media folder, Serviio wasn't notified, force refresh was needed.
This duality caused that it was hard to pinpoint the root (hehe) of the problem.
Anyway, changing to full path solved the not working part (no more force refresh).