Change in minimum guaranteed speed, why?

[#1]

Hi, when I renewed my contract this year I got an email which states:

At peak times we estimate that you'll get the following speeds on your line:

Download 43 - 49 Mbps

Upload 9 - 10 Mb

Minimum Guaranteed Speed: 39.5 Mbps

But on the website it now says

• Product:  Unlimited Fibre Extra
• Estimated Download Range:  38 - 42Mbps
• Estimated Upload Range:  9 - 10Mbps
• Minimum Guaranteed Speed:  34.4Mbps

Why would this have changed, surely it is a change to my contract that I haven't agreed? It's important because my sync speed has now fallen to 37Mbps so presumably I shouldn't be entitled to a refund...

[#2]

@fbowles Plusnet will still honour the MGS they quoted you on the renewal email, but AIUI, BT/OR have changed the way they report this to ISP's, so it can vary due to the way it is calculated.

If your sync speed has fallen to 37Mb/s that would suggest a possible problem. Can you post the results from (a) BT Broadband  and (b) BTW Performance Tester - obscuring you phone number and running/reporting the 'Advanced Diagnostic', please?

[#3]

Apologies for not replying to this, had a series of Openreach engineers scratching their head, but one suggested swapping out the cable between the faceplate and the hub, and this hopefully has solved the problem … feeling daft at not thinking about that earlier