Not so odd really, these testers have different chipsets too ....
Stranger is that they've not resolved it .... it was (as suggested) DSLAM weirdness.
i thought that maybe it have something to do with the chipset in their equipment, but then thought well surly they would know about the problem and sort it out. I know the equipment is expensive and replacing it will cost BT, but they are a massive company and make one hell of a profit.
As for my broadband, I am glad it is sorted, well sort of, if i move to another provider that says I have to use their router/modem, then I may get stuck with the same problem. i am stuck with plusnet for 2 years now anyway and to be honest the service is fine.
What get me is why did my phone line die before this problem started and what have changed since they redone the phone line?
Desktop machine now powered by windows 10 pro, reluctantly, laptop by Linux