Problem in visualisation on Android 9.0 pie

Hello!

I’m having a few problem with my interface. Well, on Android 9 (APK or companion) the application show a gap in the bottom and go further against the top bar.

I’m pretty sure it’s something simple and I look on documentation, but I didn’t find. Someone can help me with the best solution to look great on Android 9 and all other versions?

Thanks!