How to Add a delay between each device to join local server?

Need Help With My Project
9 
#define BLYNK_PRINT Serial
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
#include <SimpleTimer.h>
BlynkTimer timer;
int ReCnctFlag;


#define server "192.168.1.x" 
char auth[] = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
char ssid[] = "xxxxxxx"; 
char pass[] = "xxxxxxxxxx";
int val;
int encoder0PinA = 5;
int encoder0PinB = 4;
int encoder0Pos = 0;
int encoder0PinALast = LOW;
int n = LOW;

int curBrightness = 0;
bool isFirstConnect = true;

const int PinDT=5;    // DATA signal
const int PinCLK=4;    // CLOCK signal


BLYNK_CONNECTED() {
  if (isFirstConnect) {
    Blynk.syncAll();
    Blynk.syncVirtual(V6, V5, V3); // V6 Brightness  V5 Switch
    isFirstConnect = false;
  }


   int value = millis() / 1000;
  Blynk.virtualWrite(V33, value);
}



BLYNK_WRITE(V6) {

  curBrightness = param.asInt();
  Blynk.virtualWrite(V6, curBrightness);
  analogWrite(D5, curBrightness);
}

void setup() {
  pinMode (encoder0PinA, INPUT);
  pinMode (encoder0PinB, INPUT);
  pinMode(D5, OUTPUT);
  pinMode(encoder0PinA, INPUT);
  pinMode(encoder0PinB, INPUT);
  delay(10);
  
  Blynk.begin(auth, ssid, pass, IPAddress(192,1xx,1,x), 8080);
  Serial.begin (115200);
  while (Blynk.connect() == false) {  }   // Wait until connected
  timer.setInterval(60 * 1000, reconnectBlynk); 
}


void reconnectBlynk() {
  if (!Blynk.connected()) {
    if(Blynk.connect()) {
     BLYNK_LOG("Reconnected");
    } else {
      BLYNK_LOG("Not reconnected");
    }
  }
}

void loop() {

  
    n = digitalRead(encoder0PinA);
  if ((encoder0PinALast == LOW) && (n == HIGH)) {
    if (digitalRead(encoder0PinB) == LOW) {
      encoder0Pos--;
      if(curBrightness - 200 >= 0)curBrightness -= 100;
      Blynk.virtualWrite(V6, curBrightness);
      analogWrite(D5, curBrightness);
    } else {
      encoder0Pos++;
      if(curBrightness + 100 <= 1023) curBrightness += 100;
      Blynk.virtualWrite(V6, curBrightness);
      analogWrite(D5, curBrightness);
    }
  }
  encoder0PinALast = n;
  

  if(Blynk.connected()) {
    Blynk.run();
  }
  timer.run();
}

This is the LED Dimmer Sketch that is used

And this is the Automatic Scheduler Code (Automatic scheduler. ESP-01 with 4 Time Input Widgets) the code is too lengthy so i am putting the link.

And this the Sync Physical Button example from Blynk sketch builder

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

char auth[] = "xxxxxxx";
char ssid[] = "xxxxxx";
char pass[] = "xxxxx";

const int ledPin = 7;
const int btnPin = 8;

BlynkTimer timer;
void checkPhysicalButton();

int ledState = LOW;
int btnState = HIGH;

BLYNK_CONNECTED() {
  Blynk.syncVirtual(V2);
 }

BLYNK_WRITE(V2) {
  ledState = param.asInt();
  digitalWrite(ledPin, ledState);
}

void checkPhysicalButton()
{
  if (digitalRead(btnPin) == LOW) {
     if (btnState != LOW) {

    
      ledState = !ledState;
      digitalWrite(ledPin, ledState);
      Blynk.virtualWrite(V2, ledState);
    }
    btnState = LOW;
  } else {
    btnState = HIGH;
  }
}

void setup()
{
  Serial.begin(9600);

  Blynk.begin(auth, ssid, pass);
  Blynk.begin(auth, ssid, pass, IPAddress(192,1xx,1,xxx), 8080);

  pinMode(ledPin, OUTPUT);
  pinMode(btnPin, INPUT_PULLUP);
  digitalWrite(ledPin, ledState);

   timer.setInterval(100L, checkPhysicalButton);
}

void loop()
{
  Blynk.run();
  timer.run();
}

This is the code thats currently running on my Nodemcu’s.
I would like to repeat once again>
The problem occurs only during the devices being booted at the same time just like it would happen during a power Re-cycle.
If i turn on the devices one by one there is no problem.

Tried out scenerios

  1. Powered of Server, Router, Nodemcu. Powered them back >> Only 1 or 2 device will connect

  2. Powered of Both server and router powered them back keeping nodemcu’s on>> nodemcu will not sync back automatically and remains offline. (fewer times 1 or 3 devices come online random nodemcu’s everytime).

3)Server and router are up and running then connecting the nodemcu’s one by one>> Works as it should. No problem.

I guess i have covered all the tried out ways by me. I have tried to explain as much as i can effectively. Sorry for my bad English…