Right trigger won't work

I am using a Samsung galaxy tab pro 8.4 with a Xiaomi Mi controller. For this version and 0.14.2, the right trigger button wont work. In other games, it does work, but in MCPE it wont even acknowledge that i am pressing it in the game, or when im trying to change it in the settings. I have to set the attack/destroy button to a completely different button on the controller.