Game lags with keyboard input.

When i try and play MCC pc with a mouse and keyboard, the game lags from 250fps down to 15 fps, but, if i use a controller or move the mouse i have no issues whatsoever, i don’t know if it is to do with the keyboard it’s self being that it’s opto-mechanical, but i can’t imagine that would be an issue (razer huntsman elite), any sort of info what could possibly be causing this would be perfect, sometimes it does work fine, but 99% of the time this is an issue.

Noted this from some other users - if you razer synapse or cortex, try disabling them