Mouse and keyboard on 1000hz operating problem?

I've been playing with my polling rate settings for a few days now. With my problem, I can now rule out a placebo effect, as soon as I switch my keyboard (skillet mech 3) to 1000hz, it affects my mouse movement, I have had the same ingame sensi for years and have built up my muscle memory accordingly and notice the smallest Change and so it is as soon as I set the keyboard to 1000hz with N key rollover. Now the question arises why this is happening? Is it because both devices run at 1000hz and somehow get in the way, or whether it has another technical reason. I plugged my two devices into usb 3.0 because no other space was free, when I plugged into 2.0 the same problem. (The problem is with the keyboard or the Razer product.) Everything was tested at Fortnite!

PC:

ryzen 3600

16gb 3000 ram

MSi b450

Rtx 2070 great

ssd 500

What does the 1000 hertz keyboard do?

Reacts minimally faster when editing "f" twice