Yes having the exact same problems, always fine through the V6 boxes apps (Netflix + iPlayer) but over the last 3 months I’m getting intermittent sound stuttering that lasts half a second or so. I think its more on the HD channels. Very annoying!
Tried factory resetting the box, new HDMI, replugging cable but to no avail. Never had a problem in 3 years until recently!
I don't think this will be the cause, but for elimination purposes...
Can you try toggling PCM/stereo output via Home > Help & Settings > Settings > Audio
All that would do is mixdown multichannel Dolby Digital encoded content or convert 2 channel Dolby Digital and result in you getting 2 channel PCM. This isn't a fix and simply acts as a workaround. You'd lose the ability to access DD 5.1 if and when available if you set the box to the PCM option.
There is no fix for the issue being discussed and I've had this issue for years. It has been apparent since the V6 box was originally launched. I've had boxes replaced, wiring replaced, a promise of a firmware expert calling me to investigate this further and nothing has been done to actually fix the problem.
Virgin Media basically mark the issue as being resolved and rectified each and every time they send someone out to try fix it. It has not however been fixed. The engineers who have called do insist on setting the box to the PCM setting and then pretend they've resolved the issue. Unfortunately for them, I know what that setting does and insist they set it back to how it was set.
The issue is obviously hardware related and an issue with the V6 box itself. If it weren't then they'd have fixed it by now instead of pretending the problem doesn't exist.