Cannot send message payloads that are not multiple of 32 bytes [RESEARCH NEEDED]

[DefiCake]

Branch to track issue https://github.com/FuelLabs/fuel-bridge/tree/deficake/issue-158

Trying to pack a payload that is not multiple of 32 bytes (like in the picture) seems to conflict with fuel-core.

At relayCommonMessage.ts:

// Relay commonly used messages with predicates spendable by anyone
export async function relayCommonMessage(
  relayer: FuelWallet,
  message: Message,
  txParams?: Pick<
    ScriptTransactionRequestLike,
    'gasLimit' | 'gasPrice' | 'maturity'
  >
): Promise<TransactionResponse> {
  // find the relay details for the specified message
  let messageRelayDetails: CommonMessageDetails = null;
  const predicateRoot = message.recipient.toHexString();

  for (const details of getCommonRelayableMessages(relayer.provider)) {
    if (details.predicateRoot == predicateRoot) {
      messageRelayDetails = details;
      break;
    }
  }
  if (messageRelayDetails == null)
    throw new Error('message is not a common relayable message');

  // build and send transaction
  const transaction = await messageRelayDetails.buildTx(
    relayer,
    message,
    messageRelayDetails,
    txParams || {}
  );

  console.log(transaction);
  console.log(hexlify((transaction.inputs[0] as any).data!));
  console.log((transaction.inputs[0] as any).predicate.length);

 // This fails!!!
  return relayer.sendTransaction(transaction);
}

fuel-core will return the error:

NotInsertedIoMessageMismatch,
    #[error(
        "Transaction is not inserted. Input output mismatch. Expected coin but output is contract"
    )]

At dependency.rs:

// verify message id integrity
if !db_message
    .matches_input(input)
    .expect("Input is a message above")
{
    return Err(Error::NotInsertedIoMessageMismatch)
}