The normal response by the typical first line support entity is to categorically insist that the problem originates elsewhere. ("No, it cannot possibly be due to the physical infrastructure of the circuit . . . It has to be the end-user's modem/router."
)
I have taken a look and my initial response to your circuit's SNRM plot is "Yuck!"
I see nothing as to the origin of the problem, at the moment. We must watch and wait.
Have you performed a Quiet Line Test, with a wired telephone directly connected to the test socket of the NTE5/A? If yes, was there anything audible?
daveesh1 speculates that your circuit may be showing
similar symptoms to that of his own. I think it is currently too early to form any conclusion.