Java Collator orders the strings in French incorrectly

Question

I've been attempting to sort text in French, but been having problems.

Java Collator class seems to order some strings incorrectly.

Please suggest why this is happening?

import java.util.List;
import java.util.stream.Stream;
import java.util.stream.Collectors;
import java.text.Collator;
import java.util.Locale;

public class HelloWorld{

     public static void main(String []args){
        String s1 = "un f";
        String s2 = "une b";
        Collator c = Collator.getInstance(Locale.FRANCE);
        List<String> arr1 = Stream.of(s1, s2).sorted(c).collect(Collectors.toList());
        System.out.println(arr1);
        // outputs  [une b, un f]
        // expected [un f, une b]
     }
}