There have been various Openreach engineers out but they cant find any problems.
Here is a graph of the SNR and Sync speed over the last few days.
There are sudden drops to 0 SNR and then a resync and the line goes from around 2Mb to 1,0Mb,
The line then continues at this speed with a 9dB SNR until a sudden jump of 5dB takes it back to 14dB SNR and then a resync takes the sync speed to 2.0Mb
I have all equipment at my end disconnected apart from the modem, also a new V3 Openreach master socket was fitted so I can't see any problem at my premises.
Does this look like a common issue that could be easily spotted or is it a nightmare to find?