When I launch Destiny 2 Beta, the mouse and keyboard are delayed. I managed to fix the mouse by changing the update speed to 125. Try that if you have the same problem. However, my keyboard inputs are many seconds delayed and are held down as well. The only way I was able to play was to use a controller. This bug makes the game unplayable if you don't have a controller. I've tried using USB 3.0, a different keyboard, updated all drivers and firmware, unplugging all controllers, and it still doesn't work. It still didn't work when I switched from controller to keyboard in game. I hope this gets resolved.