Installed a new router a few days ago (Asus DSL-AC68U) everything worked - although speeds slightly less than I was getting with HH5. Unfortunately had to return the router for refund (led's on front stopped working) and went back to the HH5.
Previously the SNR had been 6.0/3.1 with download speed of 40/41Mbps now its 6.0/6.0 and download speed is 37Mbps - as it seems my line was previously on the 3db margin what are the chances of this returning?
DLM seems to be intent on maintaing the 6db margin.
as I said there is nothing you can do about noise margin apart from maintain a stable conenction and wait to see if DLM reduces margin to 3db again