My service is with Zen Internet and the package is Unlimited Zen Fibre 1 .
I've been happy for several years with consistent download speeds in excess of 30Mb/s.
For more than a week now I've been getting a much reduced service in the evenings, typically between 20:00 and 23:00 where HD streaming is not possible.. The service returns to normal each morning.
I have set up a monitoring configuration with the router connected into the Master test socket and just a single device connected - a Windows 10 PC with the Task Manager showing nothing running except my speedchecker.
Running the speedchecker at any time during the day the result shows 30Mb/s or more.
Running the speedchecker at any time between 20:00 and 23:00 the result typically shows 7Mb/s with a tbbx1 of just 1.3 Mb/s.
At any time of the day the BT Wholesale speed checker shows 30Mb/s or more.
Thanks in advance for any thoughts on what might be happening.