Arduino resets itself when connect 2 micro servos

Other Hardware Motors, Mechanics, Power and CNC
15

MarkT:
Circuit looks reasonable - have you checked the servo supply is not dropping out?

Idk, how to check ? I'am still newbie in electronics.
Code and app blocks are from this link: (note: the blocks and code are made for 10 motors but I edited them)

And the edited version of arduino code :

#include <Servo.h> 
Servo myservo1, myservo2;

byte serialA;

void setup()
{
  myservo1.attach(A8);
  myservo2.attach(A9);
  myservo2.write(180);
  Serial.begin(9600);
}

void loop()
{
  if (Serial.available() > 2) {
    serialA = Serial.read();
    Serial.println(serialA);
    unsigned int servopos = Serial.read();
    unsigned int servopos1 = Serial.read();
    unsigned int realservo = (servopos1 *256) + servopos; 
    Serial.println(realservo); 
    
    if (realservo >= 1000 && realservo <1180){
    int servo1 = realservo;
    servo1 = map(servo1, 1000,1060,0,60);
    myservo1.write(servo1);
    Serial.println("servo 1 ON");
    delay(15);

    }
    
    if (realservo >=2000 && realservo <2180){
      int servo2 = realservo;
      servo2 = map(servo2,2000,2180,0,180);
      myservo2.write(servo2);
      Serial.println("servo 2 On");
      delay(15);
    }
  }
}