Well, after an engineer coming out and replacing the Superhub 2 with a Hub 3.0 things are a little better most of the time. However the router is still dropping to one upstream channel and we are still getting connection dropouts with the log showing T3 timeouts.
This is todays graph...

Interestingly the catch-up on our TV box went off at the same time and I don't know if that is because the broadband connection went or if it was a separate connection loss to the TV box. Does the TV box use the ethernet connection for catch-up?
We have also been getting corruption on live TV channels which is shown below
[video]
I have no idea if this is coincidence, but it does make me suspect there may be an issue at the street cabinet.
Can anyone suggest anything?
Thanks!