CC2652: Am I doing something wrong while using AES CCM encryption?

I am trying to encrypt a simple message on the CC2652R which I then send over UART to a python script. Here the result is always a failed decryption. I know both the message, MAC, and Nonce arrive correctly. And both the script and the program running on the CC2652R already contain a pre-shared key.

To debug the issue I tried encrypting the same message in the python script as well, using the same PSK and Nonce. However the resulting ciphertext is different in the python script. Am I executing the AES CCM module on the CC2652R incorrectly?

This is the code on the CC2652R:

// the digest is the SHA256 result of a pre-shared salt.
// the result is the same on both the CC2652R and the python script
result = CryptoKeyPlaintext_initKey(&_cryptoKey, digest, sizeof(digest));
if (result != CryptoKey_STATUS_SUCCESS) return 1;

AESCCM_Params ccmParams;
AESCCM_Params_init(&ccmParams);
ccmParams.returnBehavior = AESCCM_RETURN_BEHAVIOR_BLOCKING;
_ccmHandle = AESCCM_open(CONFIG_AESCCM_0, &ccmParams);
if (_ccmHandle == NULL) return 0;

AESCCM_Operation operation;
AESCCM_Operation_init(&operation);
char msg[] = {'H', 'E', 'L', 'L', 'O' };
char output[5];
operation.key               = &_cryptoKey;
operation.input             = msg;
operation.output            = output;
operation.inputLength       = 5;
operation.nonce             = nonce; // the nonce is hardcoded as {0xE3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} for now
operation.nonceLength       = NONCE_SIZE;
operation.mac               = mac;
operation.macLength         = 16;
int_fast16_t result = AESCCM_oneStepEncrypt(_ccmHandle, &operation);