The hunger bar and commands

Ok so I decided to try and beat the wither in a game but usually when I eat, the hunger bar just doesn't register, the food item disappears for a second and the hunger bar actually fills up for like half a second then the food pops back into the inventory like nothing happened. Notably, this happened in the past as well but never so often in a roll, during the fight I once tired eating more then 5 times and it still didn't work, I tired turning off my shaders but nothing changes, I would like the to update this because it is very irritating. As for the commands, I have noticed that as of recent, when I try to type  something like '/gamemode' on keyboard, when I click the '/' symbol to open commands, I works but it becomes somthing more like this if I don't manually change it '/amemodeg', as you can see, the letters are wapped, now I'm not too sure if this is a personal problem or not but I would like you to look in to it.