Thanks for getting in touch, I am sorry to see you have also had trouble with your speeds.
I have taken a look and it seems you are affected by fault ref F004962952 for slow speeds at peak times. I have popped the details across to the team that deals with this type of issue and they will contact you as soon as they can with some more information. We should have more news on this fault after 1204/2017.
I do apologies I am sure this is not the news you would have liked to hear.
no not the news I was expecting , and the phrase "YoYo" it's so inconsistant , but yes generally it does improve out of hours , but these are 1am ish , so when doing Speedtest's I get anything from 30mb down to 200mb down , but average is 80mb - 150mb, but not sure this is accurate as I'll do a few right after each other, so first would be 40 then 100 then 140 then 50 then 30 then 100 then 130 then 120 then 140 , so it seems to hiccup then settle down for a while