Fibre extra dropped to 20Mbps

[#1]

I've detected that my fibre extra download speed has dropped drastically, to about a third of guaranteed minimum. Upload doesn't appear to be impacted.

From the product change email:
At peak times, we estimate that you'll get the following speeds on your line:
Download: 59 - 72Mb
Upload: 17 - 18Mb
Minimum Guaranteed Speed: 53.6Mb

I've carried out all the usual tests:

17070 QLT shows no noise on the line

the BT Wholesale speed test is returning around 18 - 20 Mbps down. Tested with a a wired connection, nothing else plugged in, wireless disabled, and into the test socket.

Looking through the router logs the only thing I can see of note is a series of PPPoE down/up overnight on the 4th and 6th October, not sure if that is enough to impact.

see enclosed screenshots

Help!

[#2]

@squawk7000 

Have you checked that your phone is working? One of the twe cores in the cable to your home can cause this. If so report a phone not broadband fault. Alternatively do a quiet line test by ringing 17070 then option 2. Again if noisy report a phone fault.

[#3 · Accepted solution]

Sorry to hear you've recently been experiencing issues with your upload speed.

I've had a look over the account and spotted something that was incorrect. If you disconnect and reconnect, your speeds should be back to normal.

Apologies for any inconvenience this caused.

[#4]

Thanks Baldrick, I have already carried out the 17070 option 2 test hearing no noise or crackle. 
calls in and out are also working ok.

[#5]

Harry, whatever you did fixed it. Back to my normal ~58 download.

Many thanks for your swift fix.

Ken

[#6]

Thanks for getting back in touch to confirm this @squawk7000 and nice work @HarryB

Dave