This happens to my friends that use mouse and keyboard on XBox one as well .I know how to resolve it for PC ..But it's up to Mojang to resolve it on XBox. 

When holding a movement key and trying to do other stuff, and action gets stuck until you repeat it . So walking foward by lava can lead to death ,and has, because I get stuck walking foward. My friend had the same issue on his PC when playing Paladins for the first time. Found this resolution and it worked on PC Paladins, but can't get into settings because Microsoft's modified windows 10 for XBox is terrible. Here it is :

"Go to Device Manager, then to Keyboards & input devices, then to the properties of your keyboard, then the Power Management Tab, and uncheck "Turn this off to save power". Do this for all other HID and USB devices. Your system turns it off while in a game, sometimes while you are holding down a key..."