Initializing a vector3 out of a function changes the result

Hello,

I’m trying to make my code more optimal by not having THREE.Vector3() creation inside useFrame().
The problem is that when I take out the declaration of m1,m2 from the const, it doesn’t work anymore. it only returns identical Box3 corresponding to the last formed Box.
I tried many different methods that all gave me the same result, like doing a function with a for loop and with .push method.
I am not sure why the function has such a behavior.

export const Player = ({  ...props }) => {
  // Some code
  useFrame((state, delta) => {
    // Some code
    boxes = myList.map((v) => AsAABB(v))
    // Some code
   })
}

const AsAABB = (v) => {
  const m1 = new THREE.Vector3()
  const m2 = new THREE.Vector3()
  boxPositions.set(v[0], v[1], v[2])
  m1.copy(boxPositions)
  m2.copy(boxPositions)

  return new THREE.Box3(m1, m2.add(BOXHITBOX))
}