No sound problems here in Teesside on my TV360.
Have you used the /check-services/ function to check for problems in your area? You can also a run a test on your equipment from there. If nothing is showing you could also try the automated Service Status number 0800 561 0061. This often gives details of more local issues down to postcode level.
Check all VM cabling and also HDMI cabling.
The picture is 2160p HLG HDR BT.2020, and sound is PCM
Have you tried changing the V6 sound settings?
Home > Help & Settings > Settings > Audio >
If your TV is not set up to work with Dolby output, select Dolby Digital, then choose Dolby Digital to PCM. Press OK on the Virgin TV remote to confirm your selection and see if that improves the sound.