Macro reaction time

I have used these macros for years and love them. I recently switched to a new keyboard G815 from a G510. The keyboard is great but…i hit the button to start my macro…I hit the button again to stop the macro. They used to stop as soon as press the button the second time. Now when I press butto nthe 3nd time the macro fires for about another 2 seconds before it stops. What could be the cause of this?