DietPi/Squeezelite and iPeng -- No Sound

Having recently purchased an Allo DigiOne, I was keen to experiment with Squeezelite – after having successfully played around with the Allo as Roon Bridge, and with the Allo and GMRender/BubbleUpnp.

So I installed LMS on my QNAP, and iPeng on my iPad Pro. In iPeng, I can “see” the QNAP as server and the DietPi/Squeezelite as player – but I cannot “squeeze out” any sound. My DAC/Streamer (Naim ND5XS) doesn’t appear to receive any signal from the Allo/Squeezelite.

Any clue what I might be doing wrong? To be honest, I am not even sure about the source of the problem: Allo DigiOne (though it works with Roon and GMRender), DietPi/Squeezelite or iPeng. Any advice would be hugely appreciated, especially since I was really looking forward to experimenting with Squeezelte and iPeng!

Many thanks,
Timo