Are you on ADSL Max as far as you know? Because your new speeds that you gave are impossible on that. They are typical of ADSL2+.
The link you give asks for postcode. That isn�t much use to me. Clearly samknows isn�t up to date. It does show Tetford as ADSL Max only, which in fact proves my previous post is correct.
BT Wholesale is in the process of upgrading all such exchanges to WBC (21CN). Scroll down
this article to the quote from a Press Release or slide showing a map and giving details. Plus the first paragraph summary.
My broadband basic info/help site -
www.robertos.me.uk. Domains, site and mail hosting -
Tsohost.
Connection - AAISP Home::1 80/20. 200GB. Sync 68543/12313Kbps @ 600m. BQMs -
IPv4 &
IPv6
Edited by RobertoS (Mon 16-Jul-18 09:05:29)