I'm also having this same issue and it's only occured since we had a 4k TV. Sometimes it works, sometimes it doesent. Driving me mad!
Is there a fix?
Sorry to hear about the issues you've had.
Have things improved at all since this?
I have same problem with bbc iplayer, stv player and YouTube. Have tried rebooting from mains.
Very frustrating. How do I resolve?
I am sorry to hear that, are you still having issues with this?
I also have this problem but only on cable v6
I purchased a new 4k TV on black Friday, bbc I player works on normal TV but won't work on cable
I have rebooted connected with new account looked at all settings but still can't get it working good audio just no picture