I am using this function to encrypt strings with a custom key in Laravel

use IlluminateEncryptionEncrypter;

public static function aes_256_cbc($str, $key){
   $Encrypter = new Encrypter($key, 'AES-256-CBC');
   return $Encrypter->encrypt($str);
}

Then, use CryptoJS to decrypt it, I have searched and used many ways but still getting this problem:

var encrypted_json = JSON.parse(Base64.decode(encrypted));

// JSON Parsed
// {
  // iv: xxx==,
  // value: xxx+5+bUEKbwGaUHB6…f2/xxx/qaphls6ybd/xxx==,
  // mac: xxx4c3aa002712ef5d7e80226bxxx,
  // tag:
// }

var key = CryptoJS.enc.Utf8.parse(mykey); 
var iv  = CryptoJS.enc.Utf8.parse(encrypted_json.iv);  
var decrypted = CryptoJS.AES.decrypt(encrypted_json.value, key, {
    iv : iv,
    mode: CryptoJS.mode.CBC
});
let res = decrypted.toString(CryptoJS.enc.Utf8)

Got this error:
Error: Malformed UTF-8 data

This problem can be easy to solve if I encrypt string by a custom function in Laravel, but it will be better if I can get a solution with CryptoJS. Can you help me?