well your problem is that your favorite movement speed exceeds the maximum turing speed in the game
see you prefer lets say 360 in 3 cm but the game only goes up to 360 in 4 cm
that means whenever you exceed the maximum turn speed in the game, your xim3 will show a black dot thus you are no longer 1:1
the fact that you are using 40 sensitivity with 5700 clearly shows this
as you are a high sens player, you probably only do flick movements, so here comes the next thing
there is no acceleration in the game, its the mechanic of the game itself
doing a constant movement will always be faster than doing a flick movement on a console
the reason is the mechanic of the analog sticks
you cannot do flick movements with an analogstick but constant movements, therefore the whole mechanic is layed out for constant movements
so if you have the need to turn around very fast you will have to get used to make a slow constant movement rather then throwing the mouse onto the other end of the mousepad
maybe those 2 pictures are helping you (or just watch the tutorial video about black dotting)
Correct Way to Play

Incorrect Way to Play

(credits to mist for the pictures

)