Try using this link if the app does not work https://www.samknows.com/realspeed/
here are some tips I used and it managed to work but also check u have the latest version. When you try any below make sure you are near the hub and you are connected to the network.
1)If you reboot ur hub by a pinhole reset and then try the connect app.
2)clear the cache and data on the app on ur device and give it a try again.
3)delete app and reinstall