Auto Power Off - not working :(

Using Arduino Project Guidance
11

Thank you for the suggestions.

I've tried to add a pull-down resistor (in option 2):

But it has no effect. As soon as I give power, the board goes on. Another strange thing is that, after 10 blinks I set digital pin2 LOW, but it has no effect (the board remains on).

void setup() {                
  pinMode(2, OUTPUT);
  digitalWrite(2, HIGH);   // keep power on
  
  // initialize the digital pin as an output.
  // Pin 13 has an LED connected on most Arduino boards:
  pinMode(13, OUTPUT);     
}

void loop() {
// do something  
for (int i=0;i<10;i++)   // blink LED ten times
     {
	  digitalWrite(13, HIGH);   // set the LED on
      delay(3000);
      digitalWrite(13, LOW);    // set the LED off
      delay(2000);
	 }
  
digitalWrite(2, LOW);  // force power off   <<<<<<<<<<<<<<
}

I also tried connecting the pulldown resostor from digital pin 2 to ground...same behaviour...

I'll try to add a cap, but I really don't understand why, setting pin2 LOW, it does not cut power...