Hi Robbo1973 👋.
Thanks for reaching out to us, sorry to hear some of the programs are out of sync in terms of audio, this is related to the set up of your sound equipment and the program quality. Netflix and UHD quality is higher than most others are SD/HD. Can we ask the set up of your sound system, if you are using optical cable, bluetooth or phono, it cannot transfer sound quality like on Netflix and UHD channels. To ensure that you have all channels in sync with the picture you would need to have a HMDI lead 2:1 from the Denon soundbar to the TV HMDI output (ARC) then the Virgin TV box HDMI to tv HDMI available slot. and then ensure your tv audio settings are for HDMI.
We hope this helps