LAUNCHXL-CC1312R1: AES128 CBC

i working on AES CBC 128, 

my problem is on AESCBC_getNextIv(),

when i run this, all the IV go to zero(which should not be,

the .h it tells:

/**
 *  @brief Returns the IV for the next block to encrypt or decrypt.
 *
 *  When encrypting or decrypting messages in multiple segments, it is necessary
 *  to save the intermediate iv to use with the next message segment.
 *
 *  Only call this function after a successful call to #AESCBC_oneStepEncrypt()
 *  or #AESCBC_oneStepDecrypt() and before starting another operation with the
 *  same handle.
 *
 *  @param  [in]    handle  A CBC handle returned from #AESCBC_open()
 *
 *  @param  [out]   iv      IV of the next block to encrypt or decrypt
 *
 *  @retval #AESCBC_STATUS_SUCCESS  The operation succeeded.
 *  @retval #AESCBC_STATUS_ERROR    The operation failed.
 */
int_fast16_t AESCBC_getNextIv(AESCBC_Handle handle, uint8_t *iv);

my code :

uint8_t iv[16] =                {
                                  0x2D, 0x2C, 0x07, 0x71, 0x94, 0x15, 0x01, 0x02,
                                  0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3
                                };

void aes_encrpyt(void)
{
    int_fast16_t next_iv_f = 0;
    aes_handle = AESCBC_open(Board_AESCBC0, NULL);

    // Initialize symmetric key
    CryptoKeyPlaintext_initKey(&cryptoKey, keyingMaterial, sizeof(keyingMaterial));

    AESCBC_Operation operation;
    // Set up AESCBC_Operation
    AESCBC_Operation_init(&operation);
    operation.key               = &cryptoKey;
    operation.input             = plaintext;
    operation.output            = ciphertext;
    operation.inputLength       = sizeof(plaintext);
    operation.iv                = iv;

    encryptionResult = AESCBC_oneStepEncrypt(aes_handle, &operation);
    test001 = encryptionResult;
    if (encryptionResult != AESCBC_STATUS_SUCCESS)
    {
        // handle error
    }

    //testing here
    next_iv_f = AESCBC_getNextIv( aes_handle,iv);
AESCBC_close(aes_handle);
    //return NULL;

}

So can someone pinpoint to me why does it happen?

Second question , do we need to handle the padding in AES CBC 128 mode?(i assume yes)
thanks

Jeff