[SlyRipper]

I don't believe this is a common failure of kodi, playing files from a network storage.

No it isn't, so let's see if we can pin down what the particular issue is here.

The obvious thing is to check your settings. Is Settings>Player Settings>Music Play next song automatically enabled?

yep that's enabled, but I could also diasble it as it only works within album folders when i get the description right.

Also make sure "Queue songs on selection" is NOT enabled, I fell into that trap the other week.

It's disabled, as I want to control my playlists manually So usually i press play/ok on the first song, and then using the context menu to add additional songs
I'm going to try creating pre-set custom/smart lists, if that works better, than the temporary playlist.

Does the NAS put its disks to sleep? My hard drives are set to spin down if not used for 1 hour. So accessing files after more than that hour, it needs to spin up the disks first

It will set the hard drives to sleep when they're not used, but I can surely exclude that issue. As said, it works when pressing next before the current song ends (sometimes), whenever it moves automatically to the next song it most likely get's stucked. when I press next now, I have to wait several seconds while kodi seems to give no feedback/response and after a while it start playing the next song as if nothing had happend. So I would assume that this is caused due to a failure in buffering or preloading the next song. I hope some settings could cure this stuff, because playing each song alone works as it should.