PHP equivalent of bitwise operation NodeJs script

I'm trying to convert a pretty simple function from NodeJs to PHP. I think I found out how to convert 80% of it, but I am stuck around bitwise operators.

This is the original NodeJs script:

function convert(encodedString) {
  let bytes = new Buffer.from(encodedString, 'base64')
  let code = bytes[bytes.length - 1]
  code ^= 91

  for (let i = 0; i < bytes.length - 1; ++i) {
    bytes[i] = ((bytes[i] ^ (code << (i % 5))) | 0)
  }

  return bytes
}

And this is the converted PHP version

function convert($encoded)
{
    $bytes = unpack('C*', base64_decode($encoded));
    $code = $bytes[count($bytes)];
    $code ^= 91;

    for($i = 0; $i < count($bytes) - 1; ++$i) {
        $bytes[$i + 1] = (($bytes[$i + 1] ^ ($code << ($i % 5))) | 0);
    }  

    return $bytes;
}

This somehow works until the bitwise part. I get the correct result for the first element of the array, but all the consequent values are wrong. I also had to adapt indexing because with the unpack method i get an base-1 index array.

If I loop each array's value before the conversion, I have the same result on both scripts, so I think is correct until that.

I was able to reproduce the issue on NodeJs, if for example I define a normal array (with same values) instead using Buffer.

I don't really know how to reproduce the same behaviour in PHP.

Any help is appreciated!