Terrible slow broadband at peak times

[#1]

Hi
Have been wit plusnet for more than 12 months now and since past few weeks i noticed my BB speeds are becoming terrible slow during peak times (evening between 6-10 mainly). I get around 12Mb speed during the day and it suddenly drop to 1.3Mb in the evenings.   Can you pleas investigate whats happening in my area?
Thanks!

[#2]

Can you run through the BT Speedtester at a time when you're having the issues and report this as a speed fault here: https://faults.plus.net