Hey there,
Checked your modem for you, The specs appear to be out a bit, Hence the 80mb,
Downstream RX Power 10.2 dBmV 10.4 dBmV 10.6 dBmV 10.5 dBmV 11.2 dBmV 10.9 dBmV 10.4 dBmV 9.8 dBmV
The above figures need to be as close to 0 as possible, betyween 0DBMV and 7DBmv is OK, These are sitting above ten, Unfortunately i cant fix this for you, You will require a engineer, Log a ticket with VM residential and Swansea centre will sort this out for you, When you speak to them ask for them to check the "levels" Engneer will be required to attenuate the service for you. This may be having a knock on effect with the other problem you are having, I would also check what rainmaker has mentioned above as well. Cheers.