Why does Swift NumberFormatter require a non-breaking space to work properly?

Question

I have a UITextField with a mask formatting my input to the BRL currency, so input 1700 from keyboard results in R$ 1.700,00 text, but since I need this value as double, NumberFormatter was used like this:

var currencyFormatter: NumberFormatter {
    let formatter = NumberFormatter()
    formatter.locale = Locale(identifier: "pt_BR")
    formatter.numberStyle = .currency
    formatter.maximumFractionDigits = 2
    return formatter
}

But when I tried to convert to NSNumber it gives me nil.

let input = "R$ 1.700,00"
currencyFormatter.number(from: input) // prints nil

Oddly, the converter works when a number is provided, and the string result can be converted to a Number.

let string = currencyFormatter.string(from: NSNumber(1700.00)) // prints "R$ 1.700,00"
currencyFormatter.number(from: string) // prints 1700.00

I started to investigate and find out what the difference is between my input and the resulting currencyFormatter string from the code below.

let difference = zip(input, string).filter{ $0 != $1 } // Prints [(" ", " ")]

It may look the same but currencyFormatter generates a string with a non-breaking space after the currency symbol while my input has a normal space. Replacing my input space with a non-breaking space makes the formatter work properly.

let nonBreakingSpace = "\u{00a0}"
let whitespace = " "
var convertedInput = "R$ 1.700,00".replacingOccurrences(of: whitespace, with: nonBreakingSpace) // prints R$ 1.700,00 or R$\u{00a0}1.700,00

currencyFormatter.number(from: convertedInput) // Now it works and prints 1700.00

Finally my question is, why does NumberFormatter with a currency numberStyle only work with a non-breaking space in this scenario?