STM32 UART DMA can receive first time correct then it receive nothing - stm32

Question

I'm trying to use dma with uart in stm32f746 nucleo.
In receiving mode I can receive correct data in first use. When i try to receive again, receiving buffer doesn't change its initial values before receiving although I can get receive complete signal callback every time.
/* Main Loop */
while(1)
{
HAL_GPIO_TogglePin(LED_PORT,LED_GREEN); // Led Example
HAL_Delay(200);
pRxData[0]=5;
pRxData[1]=0;
// HAL_UART_Receive_IT(&UartHandle,pRxData,2);
if( HAL_UART_Receive_DMA(&UartHandle,pRxData,2)==HAL_OK); // UART-DMA-IT Example
{
while (UartReady != SET) // wait for msg len
{
HAL_GPIO_WritePin(LED_PORT,LED_GREEN,1);
HAL_Delay(20);
HAL_GPIO_WritePin(LED_PORT,LED_GREEN,0);
HAL_Delay(400);
}
UartReady = RESET; // reset transmition flag
LEN = pRxData[0]+pRxData[1]*256; // calc msg length
if ( LEN > 0 )
{
pTxData[0]= 25;//LEN; // ACK
//HAL_UART_Transmit_IT(&UartHandle,pTxData,1);
if(HAL_UART_Transmit_DMA(&UartHandle,pTxData,1)==HAL_OK);
{
while (UartReady != SET)
{
HAL_Delay(1);
}
UartReady = RESET;
if(HAL_UART_Receive_IT(&UartHandle,pRxData,LEN)==HAL_OK)
{
//HAL_UART_Receive_DMA(&UartHandle,pRxData,LEN);
while (UartReady != SET) // waiting loop for msg
{
HAL_GPIO_WritePin(LED_PORT,LED_GREEN,1);
HAL_Delay(300);
HAL_GPIO_WritePin(LED_PORT,LED_GREEN,0);
HAL_Delay(50);
}
UartReady = RESET;
if (MBU_StrCompareNC(pRxData,"LED_ON_BLUE",LEN)==0)
{
HAL_GPIO_WritePin(LED_PORT,LED_BLUE,1);
}
if (MBU_StrCompareNC(pRxData,"LED_OFF_BLUE",LEN)==0)
{
HAL_GPIO_WritePin(LED_PORT,LED_BLUE,0);
}
if (MBU_StrCompareNC(pRxData,"LED_ON_RED",LEN)==0)
{
HAL_GPIO_WritePin(LED_PORT,LED_RED,1);
}
if (MBU_StrCompareNC(pRxData,"LED_OFF_RED",LEN)==0)
{
HAL_GPIO_WritePin(LED_PORT,LED_RED,0);
}
}
HAL_UART_Abort(&UartHandle);
}
}
}
}
}