Is Intl.NumberFormat formatting correct for Poland?

I have noticed that the formating of several countries (Poland, Russia, France and more) follows a strange behaviour. The format starts to apply on values with more that 4 digits. You can see it in the code below.

Unfortunately I haven't found any international standards for that and I have seen that in other programing languages the format for this countries starts from the 4th digit.

I am wondering if the Intl.NumberFormat follows the correct formatting standards.

const simpleFormat = new Intl.NumberFormat('pl-PL', {
  style: 'decimal'});
let short = simpleFormat.format(1234);
let long = simpleFormat.format(12345);

console.log(short);
console.log(long);

Expected output:

1 234

12 345