What graphics driver version are you using? I presume it's Crimson?
To configure an application to use the discrete GPU you need to open Radeon Settings > Preferences > Additional Settings.
In CCC Slim, navigate to Switchable Graphics Application Settings. This area will allow you to select which 3D application uses the Integrated GPU or the High Performance GPU. Add the application to CCC and select High Performance Mode to ensure that the High Performance GPU is used. Note, it is recommend to have the laptop plugged in and Windows configured to High performance mode in the Control Panel > Power options to ensure you get the best possible performance.