Strange behavior while working with reference

I am working on big code base. While refactoring some code I found some strange behavior related to reference. Below is minimal code to explain my question.

#include <iostream>

int main() {
  // case 1
  {
    int start = 1;
    const int &eRef = start > 0 ? start : 9;
    start = 2;
    std::cout << start << eRef;
  }
  std::cout << std::endl;
  // case 2
  {
    int start = 1;
    int end = 9;
    const int &eRef = start > 0 ? start : end;
    start = 2;
    std::cout << start << eRef;
  }
  std::cout << std::endl;
  return 0;
}

Output of above code is

21

22

I am expecting output 22 for both case. But getting different output for both case.

It might be as per standard, but I would like to know reason behind it.