As john46 already said you are on infinity 2 but your noise margin is higher than normal 6db. This is normally the result of line noise and/or router dropping connection and your connection won't improve until the problem is fixed and you get back to a stable connection
if line noise you can report phone fault to 151 otherwise it is CS India
I see in this thread https://community.bt.com/t5/BT-Infinity-Speed-Connection/THE-WORST-EVER-FIBRE-BROADBAND/td-p/1440160... that you hadn't taken up the offer of a moderators help but they have offered it yet again so I would suggest that you take up this offer now.
I'm glad I was able to help sort out your broadband speed.
Your broadband speed was banded so it took an engineer visit to reset the SNR at the cab and get your speed back up to what it should be at. Really pleased everything is looking Hunky-Dory now!
All the best,