It looks as though whatever work they did has been left with the network not being properly lined up.
Your upstream transmit is too low. I suspect that's the case for more people in your area.
Wherever the planned work was done they either need to lower the return path gain or add attenuation to get your modems transmitting at a higher power and get them higher above the noise floor.
This needs a network engineer. The planned works don't seem to have quite been done right, your upstream transmit seems 6 dBmV lower than it was and unless the cable plant is insanely clean 64QAM is challenging.
Your actual stats in terms of modulation and T3s fit with this. The lower frequencies are naturally more noisy so the idea that there's no real obnoxious source of noise just upstream transmit is too low to give a high enough noise margin over the regular noise floor fits.
Thanks ipfreely I thought it was a network problem and needed networks to look into it but trying to get virgin to refer it to them seems difficult, all they seem to want to do is to send a tech out to my property and the tech will probably say he or she can't find a fault and I get charged 25 pounds when I'm quite sure like u said that it needs a network engineer as problems only started when they upgraded the network.
