Hello Mrs. Rodrigues,
I am writing you because the ticket you created to us.
Could you please check if following function is being called? That should be the one processing the message buffer.
void Flexio_Sent_Ip_IRQMsgDataHandler(const uint8 Instance, const uint8 HwChannel, uint32 TimerVal)
The buffer pointed by this pointer should contain the received messages:
Flexio_Sent_Ip_axFastData