@Anonymous User
So it's only happening when watching 5 Star or plus 1 whilst watching the channel over long periods, where watching the channel for shorter periods is not effected ?
What sort of time period are we looking at before the sound cuts out ?
When watching other Freeview channels for long periods of time the sound is not effected ?
If it was effecting all channels over longer periods then i would say at a guess it may be something like the box was possibly overheating.
Is your smart box plugged directly into your TV or are you using a sound bar or AV Receiver ?
Note sure what to suggest apart from the basics, such has try a rescan the TV channels on the box, play around with the sound settings on your box /TV, check for software updates or maybe factory reset the box (however not sure if this will fix your sound problem, but no harm in trying).
Hopefully other helpful forum members on here will come up with some more suggestions.
