<p>The BT Sport app closed on 12th October and has been replaced by discovery+. <a href="https://community.bt.com/t5/TNT-Sports-on-TV-Online-player/The-BT-Sport-app-is-closing-on-12th-October/td-p/2312034">Find out more about activating TNT Sports on the discovery+ app</a>.
First thing I would try is to move your Hub to a fixed WiFi channel such as Channel 1 rather than let it try and decide for itself. You may be getting reduced speeds due to conflicts with neighbouring equipment. It takes moments to do... just search for your Hub type and how to change channels.