keyboard not activated when playing Fortnite with iPad

I have an iPad Smart Keyboard by apple and a third party mouse connected to my ipad. The mouse works fine for all applications. However, while the keyboard works for other applications, it is deactivated for some reason during Fortnite play. The mouse functions during Fortnite play, but the keyboard does not, forcing me to use the touch screen. Does anyone know how to fix this so that I can use the keyboard for play?