Has anybody got their audio out working on the Veon TV?

I've connected my Hi-Fi system, changed the input to AUX on the Hi-Fi, yet the sound still comes from the TV speakers. How do I get my speaker to play the sound? I can't find anything in the TV config to force sound to the audio out jacks.
Link to manual 49" version of 4K TV.
Edit:
Sound keeps playing on TV, no matter the input
- DTV
- Chromecast via HDMI
- PC via HDMI
I have also changed between the HDMI & HDMI (ARC) ports.


