2-way wireless connection 1 master + 2 slave to nRF24L01 using Arduino

I have a project that uses multiple nRf24l01 to connect two ways together to send sensor signals to one master. This is the master's code:

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>

RF24 radio(9,10);
const byte addresses[][6] = {"00001", "00002","00003","00004","00005","00006"};

struct but1{
  int a = 3;
  int b = 4;
}set1;

struct but2{
  int c;
  int d;
}get1;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  radio.setPALevel(RF24_PA_MAX);
  radio.openWritingPipe(addresses[1]); 
  radio.openReadingPipe(1, addresses[0]); 
  radio.openWritingPipe(addresses[3]); 
  radio.openReadingPipe(2, addresses[2]); 
  radio.openWritingPipe(addresses[5]);
  radio.openReadingPipe(3, addresses[4]);                          
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(5); 
  radio.stopListening();
  radio.write(&set1,sizeof(set1));
  delay(10);
  radio.startListening();
  radio.read(&get1,sizeof(get1));
  Serial.print(get1.c);
  Serial.println(get1.d);
}

and here is the code of salves:

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>

RF24 radio(9,10); // CE, CSN
const byte addresses[][6] = {"00001", "00002"};
String data;

struct dataStruct{
  int a;
  int b;
}get1;

struct node{
  int c;
  int d;
}set1;

void setup() 
{
  Serial.begin(9600);
  radio.openWritingPipe(addresses[0]); // 00001
  radio.openReadingPipe(1, addresses[1]); // 00002
  radio.setPALevel(RF24_PA_MAX);
}

void loop() 
{
  delay(5);
  radio.startListening();
  radio.read(&get1,sizeof(get1));
  Serial.print(get1.a);
  Serial.println(get1.b);
  delay(10);
  radio.stopListening();
  set1.c = 10;
  set1.d = 9; 
  radio.write(&set1,sizeof(set1));  
}

And

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>

RF24 radio(9,10); // CE, CSN
const byte addresses[][6] = {"00003", "00004"};
String data;

struct dataStruct{
  int a;
  int b;
}get1;

struct node{
  int c;
  int d;
}set1;

void setup() 
{
  Serial.begin(9600);
  radio.openWritingPipe(addresses[0]); // 00003
  radio.openReadingPipe(2, addresses[1]); // 00004
  radio.setPALevel(RF24_PA_MAX);
}

void loop() 
{
  delay(5);
  radio.startListening();
  radio.read(&get1,sizeof(get1));
  Serial.print(get1.a);
  Serial.println(get1.b);
  delay(10);
  radio.stopListening();
  set1.c = 8;
  set1.d = 7; 
  radio.write(&set1,sizeof(set1));  
}

The first slave is very stable. But the second slave is very unstable in the receiving and sending directions, the output signal is 00. Looking forward to everyone's help.