my if statement doesn't work when checking radio input

Im trying to validate radio input to check if its correct answer.
But it skips the line if (answer == allQuestions[q].correctAnswer)

here is whole code https://jsfiddle.net/alcatel/sopfmevh/1/

for (let k = 0; k < answers.length; k++) {
  if (answers[k].checked) {
    answer = answers[k].value;
  }
}

// IT SKIPS THIS LINE !!
if (answer == allQuestions[q].correctAnswer) { // IT SKIPS THIS LINE!!
  alert("correct");
}

q++;
    
populate();