Line speed drop - any advice?

[#1]

My most recent sync is

8:13:40, 27 Mar. ( 134.650000) PPPoE is up -​ Down Rate=42301Kbps, Up Rate=18143Kbps;
SNR Margin Down=5.9dB, Up=5.7dB

This is now well below the BT estimate 

                             Downstream Line Rate(Mbps) Upstream Line Rate(Mbps) Downstream Handback Threshold(Mbps)
                                           High Low                                      High Low
VDSL Range A (Clean)      74.8 52.2                                       20 14.8                                                 44

It has been falling in stages, but this is a new low

02:03:24, 08 Aug. ( 131.150000) PPPoE is up -? Down Rate=51300Kbps, Up Rate=19680Kbps;

SNR Margin Down=6.1dB, Up=6.0dB

00:11:26, 21 Dec. (4584969.870000) PPPoE is up -? Down Rate=47372Kbps, Up Rate=17375Kbps;
SNR Margin Down=5.9dB, Up=5.8dB

19:36:36, 29 Jan. ( 129.020000) PPPoE is up -? Down Rate=46249Kbps, Up Rate=17777Kbps;
SNR Margin Down=5.9dB, Up=5.9dB

[#2]

Hi there, line tests aren't picking up on any obvious problems but it would be worth going down the route of raising a fault if you notice that fluctuating to such a degree again.

[#3]

Many thanks for replying and line testing. I waited 24 hrs and re-synched and it's back to how it's been for the last 3 months - still below the BT estimate but I don't think an engineer visit will really help yet - unless they lay a new cable that is ! I've already/ got a recent face-plate etc

19:28:58, 28 Mar. ( 129.550000) PPPoE is up -​ Down Rate=46092Kbps, Up Rate=17278Kbps;
SNR Margin Down=5.9dB, Up=5.8dB

[#4]

Glad to hear your speeds have improved.

If your speeds drop anymore I'd recommend raising a fault here so we can arrange an engineer just to make sure there's no problems on the Openreach network.

[#5 · Accepted solution]

Cheers for reporting the fault. 

I've just sent a reply to your ticket.