Internet not working how it should

[Brand]

Internet speed aren't up to standard everything is lagging but broadband and WiFi say it's running at over 400 mbs. It isn't

[JimM1]

@Brand How do you know?

[Brand]

My sky app says everything is running perfectly speed checkers say it too but I can guarantee it isn't because whatever I do I.e stream something on tv work on the computer it just lags

[JimM1]

@Brand So you are saying then that you have a wireless issue is that correct? What hub do you have from sky, Black or White?