I think the formula for Kraft must be different in the UK where I grew up, vs the USA where I live now.
I have already proved that US Kit Kats (made by Reese/Hershey) have almost no chocolate smell compared to Euro Kit Kats (made by Nestlé) which have a rich cocoa aroma.
My wife and I noticed that right away and it’s nice to have confirmation. We don’t eat it all that often but it was around that time we noticed it was less flavorful. We started buying powdered cheese to add in.