Mouse still lag

Hello, first it's a pleasure to be able to help you today.

My name is welcome to the community.

Hello Sentoise1, the console has by definition the use of the mouse and keyboard activated, however the developer is in charge of the settings in the game.

Try to do the procedures below and then see the settings in Fortnite.

Xbox One reset keeping Games:

Press the Xbox button to open the panel.

Select system > Settings > System > Console Information

Select Reset console.

Restore and maintain my games and apps.

Rest assured, you won't miss games or saves

Note: You need to know the email and passwords of your accounts when performing this reset.

Release date

12/13/2018

Mouse

Improved the responsiveness of mouse performance to reduce lag.

System

Improved system performance.

Polling rate is not completely relative to Input lag. This is often an issue with the xbox console. If you experience input lag then I suggest unplugging and replugging your mouse

lag depends on what server you choose just as much chance of it happening in the console version, the main issue i have as OP sates is keyboard and mouse. I wanted this on the pc as i recently got a top rig, but can't get used to keyboard and mouse, i have
tried my 360 controller on the pc beta, but against people with an accurate mouse it's very hard.

So i'm still decideing what system to buy on.

As a side note, when the app is full screen and I move my mouse to bring up the toolbar on top, the choppiness and lag stops and the stream is very smooth. As soon as I stop moving the mouse and the toolbar and mouse pointer fades away, it gets choppy again.