MinimServer & Naim NDX/n-Stream Playlists errors

[blinkeye]

MinimServer : 0.8.2 update 42 (running on up-to-date QNAP NAS TS-269 Pro)
MinimStreamer: 0.4.3 (running on up-to-date QNAP NAS TS-269 Pro)


Naim N-Stream: v4.2, Build 9940
Naim NDX: v3.23 (yes, stock version!), Firmware Version: 2.0.50.12943


Problem: whenever creating a playlist with the N-Stream app (which creates the playlist not on the MinimServer but on the Naim NDX renderer) the tracks get properly added and the playlist can be used. After a while (sometimes during the same day) some tracks if not all get lost and cannot be played anymore (title is no longer available or server is offline). Some of the tracks get a yellow exclamation mark in the N-Stream app, some a red/white cross and very seldom one single track is still playable.

I do not reboot/restart the NAS or the MinimServer, nor even rescan the music library or change it in any way.

And yes, restarting the N-Stream app and resetting/clearing the cache does not help.

My questions:

1. is this a known problem?
2. is MinimServer somehow re-arranging the tracks?
3. what can I do to help tracking it down?
4. how would one access and test such a playlist (i.e. the specific items) just to verify it's not a minimserver issue?