WIFI Module blocks data reception on UART

[Erenburg.Evgeny]

I have STM32L475VC + ISM43362 WIFI Module.

Set module, connect to AP.

if(ISM43362_Init() == WIFI_STATUS_OK)
    {
        USART_SendString(SYS_USART, "WIFI INIT OK\r");
        if(WIFI_GetMAC_Address(mac_addr) == WIFI_STATUS_OK)
        {
            USART_SendString(SYS_USART, "MAC ADDRESS ");
            USART_SendHex(SYS_USART, mac_addr[0],0);
            USART_SendString(SYS_USART, ":");
            USART_SendHex(SYS_USART, mac_addr[1],0);
            USART_SendString(SYS_USART, ":");
            USART_SendHex(SYS_USART, mac_addr[2],0);
            USART_SendString(SYS_USART, ":");
            USART_SendHex(SYS_USART, mac_addr[3],0);
            USART_SendString(SYS_USART, ":");
            USART_SendHex(SYS_USART, mac_addr[4],0);
            USART_SendString(SYS_USART, ":");
            USART_SendHex(SYS_USART, mac_addr[5],1);
        }
    }
    else
      USART_SendString(SYS_USART, "WIFI INIT ERROR\r");
 
if( WIFI_Connect(SSID, PASSWORD, WIFI_ECN_WPA2_PSK) == WIFI_STATUS_OK)
    {
        if(WIFI_GetIP_Address(ip_addr) == WIFI_STATUS_OK)
        {
            USART_SendString(SYS_USART, "Connected: got IP Address ");
            USART_SendInt(SYS_USART, ip_addr[0], 0);
            USART_SendString(SYS_USART, ".");
            USART_SendInt(SYS_USART, ip_addr[1], 0);
            USART_SendString(SYS_USART, ".");
            USART_SendInt(SYS_USART, ip_addr[2], 0);
            USART_SendString(SYS_USART, ".");
            USART_SendInt(SYS_USART, ip_addr[3], 1);
        }
        else
        {
	   USART_SendString(SYS_USART , "ERROR: CANNOT get IP address\r");
        }
    }
 
if (WIFI_StartServer(SOCKET, WIFI_TCP_PROTOCOL, 1, "", PORT) == WIFI_STATUS_OK)
        USART_SendString(SYS_USART, "Start server - SUCCESS\r");
    else
        USART_SendString(SYS_USART, "Start server - ERROR\r");

Everything OK.

WIFI INIT OK

MAC ADDRESS C4:7F:51:7:B5:A5

Connected: got IP Address 172.16.1.120

Start server - SUCCESS

In main.c I put a UART string reception

while (1)
{ 
      
    if (uart4_rx_ready)
    {
       uart4_rx_ready = 0;
            
       PARSER_ParseCommand(uart4_rx_buf);
    }     
      
}

It's OK. I get user commands from terminal and parse it. Commands I get char by char on UART interrupt.

Now I add a WIFI module reception

while (1)
{      
    if (uart4_rx_ready)
    {
        uart4_rx_ready = 0;
            
        PARSER_ParseCommand(uart4_rx_buf);      
    }
 
    if (WIFI_STATUS_OK == WIFI_ReceiveData(SOCKET, udp_rx_buf, 1000, &udp_rx_len, 0 ))
    {
        if (udp_rx_len > 0)
          USART_SendInt(SYS_USART, udp_rx_len, 1);
    }
       
}

 And UART reception crushes - I get a first char then I get - ORE: Overrun error.

What's wrong?