Question about the Mutations solution

Tell us what’s happening:
This seems like a silly question, but could someone please explain why the code below doesn’t solve the problem? The only differences from “solution 1” in the challenge guide is I swapped the positions of return true and return false and changed the < to >= within the if statement.

  **Your code so far**

function mutation(arr) {
let test = arr[1].toLowerCase();
let target = arr[0].toLowerCase();

for (let i = 0; i < test.length; i++) {
  if (target.indexOf(test[i]) >= 0) {
    return true;
  } 
}
return false;
}

console.log(mutation(["hello", "hey"]));
  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.164 Safari/537.36

Challenge: Mutations

Link to the challenge:

Have you tried following step-by-step one of the failing tests? What is each variable, what happens in the loop, does if condition is fulfilled, what happens if yes, what happens if not?

Try to log out some of the values. See if that doesn’t help answer your question.

function mutation(arr) {
   let test = arr[1].toLowerCase();
   let target = arr[0].toLowerCase();

   for (let i = 0; i < test.length; i++) {
      if (target.indexOf(test[i]) >= 0) {
         console.log(target)
         console.log(test)
         console.log(test[i])
         return true;
      }
   }
   return false;
}
console.log(mutation(["hello", "hey"]))