My pretty new Razer Mamba Tournament Edition is not right in the middle of Fortnite or almost not at all. Do you have to buy a new mouse or can you do it? Or is it probably synonymous s.Fernnite game?
Uninstall the drivers first and reinstall them.
Get the drivers from the manufacturer's HP.
Do you have many USB devices? Maybe your USB bus is too busy.
Unsuitable surface
Dirty optics
loose connection
Do you at least have a brush with you?