Mouse lag and screen stutter while gaming at ultra settings

hello guys 
i play battlefield V and i have legion y540 rtx 2060 with 144hz display. 
when i set to low settings fps goes to 144 and screen will be super smooth with mouse movement.
but when i set ultra settings fps will be in between 80 to 100 and screen somehow stutters while mouse movement.
what could be the issue?
I am using ordinary mouse.Will the DPI of mouse come in to picture in my case?
Should i buy high dpi mouse or any other problem with my laptop?