Why std::sort with polish collate is not working properly?

Question

I have a task to sort vector in polish locale and what im trying to do is not working. Maybe this sorting is good but I don't understand it?

This is my approach

#include <algorithm>
#include <iostream>
#include <locale>
#include <string>
#include <vector>
using namespace std;

int main()
{
  locale polish("pl_PL.UTF-8");
  wcout.imbue(polish);

  vector<wstring> v{
    L"Słoń", L"Bąk", L"Bocian",
    L"Ryś", L"Żyrafa", L"Lew",
    L"Żuk", L"Bóbr", L"Anakonda",
    L"Łoś", L"Bażant", L"Czapla"
  };

  cout << "Przed sortowaniem: ";
  for (const auto& s : v)
    wcout << s << " ";
  cout << endl;

  sort(v.begin(), v.end(), polish);

  cout << "Po sortowaniu: ";
  for (const auto& s : v)
    wcout << s << " ";
  cout << endl;
}

And what im getting is

Przed sortowaniem: Słoń Bąk Bocian Ryś Żyrafa Lew Żuk Bóbr Anakonda Łoś Bażant Czapla 
Po sortowaniu: Anakonda Bażant Bocian Bóbr Bąk Czapla Lew Ryś Słoń Łoś Żuk Żyrafa 

But for example Łoś should be after L and M. How can I get appropriate sort using only collate for polish location?