How can there be both a "usual meaning" and a "correct meaning" when you assert that there is only one meaning and "There's no possible discussion over this fact."

You can say that one meaning is more correct than the other, but that doesn't vanish the other meaning from existence.

When precision is required, you either use kibibytes or define your kilobytes explicitly. Otherwise there is a real risk that the other party does not share your understanding of what a kilobyte should mean in that context. Then the numbers you use have at most one significant figure.

The correct meaning has always been 1024 bytes where I’m from. Then I worked with more people like you.

Now, it depends.