Thanks MarioM for the feedback.
In the meantime, I continued to fight with the beast and finally managed to make it work by simply changing:
//Ds216j/music/HiRes /mnt/HiResMusic cifs user=max2play,password=squeezebox,iocharset=utf8,sec=ntlm,vers=1.0
//Ds216j/music/HiRes /mnt/HiResMusic cifs user=max2play,password=squeezebox,iocharset=utf8,_netdev
Now I can finally see again my mounted lossless folders in the Squeezebox server, but it still seems to be laggy when I stream my music… I have now to clarify if some setting has changed in my network (which was working fine under DSM 6) or if it is related to the ‚_netdev‘ setting instead of ’sec=ntlm,vers=1.0’… Maybe you have an advice about it? What does change when I use ‚_netdev‘ in the Options field?
I will also try your proposal and let you know.