why usart tx with dma work stuck after runing some times

Question

i use stm32f407 HAL to use USART TX/RX DMA, Circle DMA For RX, Normal For Tx. The RX work pretty well, But the Tx work with some abnormal after runing some times, tx dma do`t enter Transfer Complete Interrupt, I have no idea with this, Why this happened?

I have clear the flag in TC Callback after next callHAL_UART_Transmit_DMA(&huart1,pdata,len); But the tx dma do`t enter Transfer Complete Interrupt

I have clear the usart and tx dma flag. But i have no effacts

**
  * @brief  USART User TC Callback (Interrupt)
    * @param  huart: 串口句柄
  * @retval None
  */
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{
    __HAL_UART_CLEAR_FLAG(huart, UART_FLAG_TC);
    
    //huart->gState = HAL_UART_STATE_READY;
    
    if( huart->Instance == USART1 )
    {
        RS485_DIR_RX(1);                            
        usart_tx_dma_status[USART1_INDEX] = 0;
//      hdma_usart1_tx.State = HAL_DMA_STATE_READY;
//      __HAL_UNLOCK(&hdma_usart1_tx);
    }
}