Broadband very slow

[Mrs+SLP]

Over the last few weeks I have noticed a massive difference with our broadband service. It is intermittently slow multiple times. This is effecting the sky glass steaming (we have cat 6 so the TV's are connected directly to WiFi). Also using WiFi on our mobile phones is super slow. It is just not anywhere near the same service we normally get. This has been going on for weeks now. 

[Crosby69]

We have exactly the same issue - very slow broadband. It would be helpful if an engineer could run some diagnostics. 

[Herman15]

Experiencing buffering on Now and Netflix apps in the last hour. My sky app says all is well, yet speed test on Internet sites say a different story.