speed online dropping here why?

[flashgordon1952]

I have a strange problem here ? Everytime i put Sky news on ,through my internet connection on PC. ( 8 gigs memory Windows 10 ) the speed according to a broadband test ,drops by more than half then disconnect Sky news everything is fine over 220 mps ( still with normal connection ie Facebook and Yahoo . Is this speed check an accurate measure or just a guildline , what is going on . Any ideas what is going on