Nextion.available() doesn't work

[stuffpkb]

Hello all,

When clicking buttons, on the second page of the screen, nextion.available() is false all the time

Program code:

#include <DHT11.h>
#include <SoftwareSerial.h>
#include <Nextion.h>

DHT11 dht11(2);
intValue;
StringTosend;
String data; // variable for storing data

SoftwareSerial nextion(8, 9); // Nextion TX to pin 8 and RX to pin 9 of Arduino
Nextion myNextion(nextion, 9600); //create a Nextion object named myNextion using the nextion serial port @ 9600bps

void SendAdd(int id, int NumGraf, int val)
{
  
   if (NumGraf == 0) Value = map(val,0,125,0,255);
   if (NumGraf == 1) Value = map(val,0,100,0,255);

   Tosend = "add";
   Tosend += id;
   Tosend += ",";
   Tosend += NumGraf;
   Tosend += ",";
   Tosend += Value;

   nextion.print(Tosend);
   nextion.write(0xff);
   nextion.write(0xff);
   nextion.write(0xff);

}

void setup() {

     Serial.begin(9600);
     nextion.begin(9600);
     myNextion.init();

     pinMode(LED_BUILTIN, OUTPUT);
     pinMode(3, OUTPUT);
     digitalWrite(3, 1);

}

void loop()
{
  
     int temperature = 0;
     int humidity = 0;

     int result = dht11.readTemperatureHumidity(temperature, humidity);

     //update temperature and humidity text
     myNextion.setComponentText("page0.t0", String(temperature));
     myNextion.setComponentText("page0.t1", String(humidity));

     //update temperature and humidity graphs
     SendAdd(5,0, temperature);
     SendAdd(5,1, humidity);
   
     // wait for data from the display
     if (nextion.available())
     {
       char inc;
       inc = nextion.read();
       data += inc;

       Serial.println("nextion.available");

       if (inc == 0x0A) //end of command
       {
         // if 'on' came
         if (data.indexOf("on") >= 0)
         {
            digitalWrite(LED_BUILTIN, 1);
            digitalWrite(3, 0);
            data = "";
            Serial.println("on");
         }
       }

       if (inc == 0x0A) //end of command
       {
         if 'off' came
         if (data.indexOf("off") >= 0)
         {
            digitalWrite(LED_BUILTIN, 0);
            digitalWrite(3, 1);
            data = "";
            Serial.println("off");
         }
       }
      
      
     }

    
}

If excluded, the code is:

int temperature = 0;
    int humidity = 0;

    int result = dht11.readTemperatureHumidity(temperature, humidity);

    //update temperature and humidity text
    myNextion.setComponentText("page0.t0", String(temperature));
    myNextion.setComponentText("page0.t1", String(humidity));

    //update temperature and humidity graphs
    SendAdd(5,0, temperature);
    SendAdd(5,1, humidity);

Then nextion.available() works and returns true.
Tell me how to solve this problem. So that the graphs would be drawn on the first page and there would be a reaction to pressing buttons on the second page.

[stuffpkb]

Changed the button click interception code. But, unfortunately, button presses are still not intercepted if the graph is simultaneously drawn:

void loop()
{
    
    int temperature = 0;
    int humidity = 0;

    int result = dht11.readTemperatureHumidity(temperature, humidity);

    //update temperature and humidity text
    myNextion.setComponentText("page0.t0", String(temperature));
    myNextion.setComponentText("page0.t1", String(humidity));

    //update temperature and humidity graphs
    SendAdd(5,0, temperature);
    SendAdd(5,1, humidity);

    delay(500);

    String message = myNextion.listen();

    if (message == "65 1 2 1 ffff ffff ffff") //65 01 02 01 FF FF FF 
    {
       Serial.println("Green button");

       digitalWrite(LED_BUILTIN, 1);   
       digitalWrite(3, 0);
       data = "";
    }

    if (message == "65 1 3 1 ffff ffff ffff") //65 01 03 01 FF FF FF
    {
       Serial.println("Red button");

       digitalWrite(LED_BUILTIN, 0);   
       digitalWrite(3, 1);
       data = "";
    }
    
}