Questions about SPI6 and BDMA

[pass3master]

We are trying to transmit data using SPI6 and BDMA.
When we perform the following process, we are able to transmit 1 byte + 1 bit of data, but after that, MISO outputs High no matter what the value of the transmitted data is. What is wrong with this?

#define __ATTR_RAM_D3   __attribute__ ((section(".RAM_D3"))) __attribute__ ((aligned (4)))
uint8_t         g_spitxbuf[4] __ATTR_RAM_D3;            // DCDC基板温度センサ模擬_送信バッファ

    uint8_t rx_buf[2] = {0};
    uint8_t tx_buf[2] = {0};

    /* SPI3_CS High出力 */
    HAL_GPIO_WritePin(GPIOF, GPIO_PIN_6, GPIO_PIN_SET);

    /* SPI3_CLKを有効 */
    __HAL_SPI_ENABLE(&hspi5);

    /* SPI3_CS Low出力 */
    HAL_GPIO_WritePin(GPIOF, GPIO_PIN_6, GPIO_PIN_RESET);

    g_spitxbuf[0] = 0xA5;
    g_spitxbuf[1] = 0x00;
    g_result = HAL_SPI_TransmitReceive_DMA(&hspi6, g_spitxbuf, rx_buf, 2);
    g_result = HAL_SPI_TransmitReceive(&hspi5, tx_buf, rx_buf, 2, 1000);

    /* SPI3_CS High出力 */
    HAL_GPIO_WritePin(GPIOF, GPIO_PIN_6, GPIO_PIN_SET);