Button clicked when not visible

When clicking the Quiz button at a point, where the “richtig” or the “falsch” button would be, like on the left of the i, im not shown the first question, but the result screen, so the question is answered with the click on the quiz button. Does anybody know, why that is the case? You should probably try the program yourself to understand what I mean

int state = 0;
color green = color(72, 255, 0);
color red = color(255, 17, 0);
color lightblue = color(3, 182, 252);

PImage Team;
PImage Sponsoren;
PImage Produktion;
PImage Konstruktion;

int flag = 0;

// 3 parallel arrays 

String[] text1 = { 
  "1. Aussage:", 
  "2. Aussage:", 
  "3. Aussage:", 
  "4. Aussage:", 
  "5. Aussage:", 
  "6. Aussage:", 
};

String[] text2 = { 
  "Wir haben einen nicht gelisteten Helfer.", 
  "          Wir sind das erste Mal dabei.", 
  "Unser Team besteht nur aus Leuten aus der 7. Klasse.", 
  "          Unserer ITler ist der coolste.", 
  "Beim letzten Wettkampf kamen wir in die Top 5.", 
  "Unsere Schule stellt ein anderes Team.", 
};

int[] correct = {
  1, 
  2, 
  2, 
  1, 
  2, 
  1, 
};

// index for all 3 
int index = 0; 



String QUIZ = "Q\nU\nI\nZ\n";

int x1=100, y1=100, w1=250, h1=250;   //Button oben links
int x2=1570, y2=100, w2=250, h2=250;   //Button oben rechts
int x3=100, y3=750, w3=250, h3=250;   //Button unten links
int x4=1570, y4=750, w4=250, h4=250;   //Button unten rechts
int x5=80, y5=910, w5=250, h5=100;   // Button zurück
int x6=860, y6=0, w6=200, h6=1080;    //Button Quiz
int x7=260, y7=290, w7=500, h7=500;    //Quiz left Button
int x8=1160, y8=290, w8=500, h8=500;    //Quiz right Button


void drawMainButtons() { //_______ stat 0 only
  if ( over(x1, y1, w1, h1) ) stroke(255, 251, 0); 
  else stroke(0, 0, 200);
  fill(84, 0, 153);
  rect(x1, y1, w1, h1);
  fill(255, 251, 0);
  textSize(50);
  text("Team", 160, 240);
  
  
  if ( over(x2, y2, w2, h2) ) stroke(255, 251, 0); 
  else stroke(0, 0, 200);
  fill(84, 0, 153);
  rect(x2, y2, w2, h2);
  fill(255, 251, 0);
  textSize(37);
  text("Konstruktion", 1580, 240);
  
  
  if ( over(x3, y3, w3, h3) ) stroke(255, 251, 0); 
  else stroke(0, 0, 200);
  fill(84, 0, 153);
  rect(x3, y3, w3, h3);
  fill(255, 251, 0);
  textSize(45);
  text("Produktion", 106, 890);
  
  
  if ( over(x4, y4, w4, h4) ) stroke(255, 251, 0); 
  else stroke(0, 0, 200);
  fill(84, 0, 153);
  rect(x4, y4, w4, h4);
  fill(255, 251, 0);
  textSize(45);
  text("Sponsoren", 1580, 890);
  
  
  if ( over(x6, y6, w6, h6) ) stroke(255, 251, 0); 
  else stroke(0, 0, 200);
  fill(84, 0, 153);
  rect(x6, y6, w6, h6);
  draw_quiz_text();
}

void draw_zurueck_button() { //_ state 1,2,3
  fill(84, 0, 153);
  if ( over(x5, y5, w5, h5) ) stroke(255, 251, 0); 
  else stroke(0, 0, 200);
  rect(x5, y5, w5, h5);

  fill(255, 251, 0);
  textSize(55);
  stroke(0);
  text("zurück", x5 + 35, y5 + 68);
  textSize(40);
  fill(0, 0, 200);
}

void draw_low_zurueck_button() {
  fill(84, 0, 153);
  if ( over(x5, y5 + 100, w5 - 50, h5 - 50) ) stroke(255, 251, 0); 
  else stroke(0, 0, 200);
  rect(x5, y5 + 100, w5 - 50, h5 - 50);

  fill(255, 251, 0);
  textSize(50);
  stroke(0);
  text("zurück", x5 + 15 , y5 + 140);
  textSize(40);
  fill(0, 0, 200);
}


void draw_quiz_text() {

  fill(255, 251, 0);
  textSize(150);
  stroke(0);
  textLeading(250);
  textAlign(CENTER);
  text(QUIZ, x6 + 95, y6 + 220);
  textAlign(LEFT);
  textSize(40);
  fill(0, 0, 200);
}

void actOnFlag() {
  if (flag == 0) {
    // Question 1
    pushStyle();
    background(255);
    fill(255, 0, 0);
    rect (1000, 500, 300, 300);
    fill(0, 255, 0);
    rect (600, 500, 300, 300);
    fill(0, 0, 0);
    text(text1[index], 900, 250);
    text(text2[index], 650, 290);
    textSize(32);
    fill(0, 51, 0);
    text("WAHR", 700, 650);
    textSize(32);
    fill( 128, 0, 0);
    text("FALSCH", 1100, 650);
    pushStyle();
  } else if (flag == 1 || flag == 2) {  
    //
    resultScreen();
  } else if (flag == 3) {
    background(255);   

    draw_zurueck_button();

    
    flag=0;
    index++;
    if ( index >= text2.length ) state=7;
    flag=0;
  } else {
    background(255);
    textSize(32);
    fill(255, 0, 0);
    text("Error in actOnFlag: "+flag, 600, 150);
  }
}//func 

void setup() {
  fullScreen();
  //size(1920, 1200);
  fill(0, 0, 200);
  strokeWeight(10);
  Team = loadImage("Team.png");
  Sponsoren = loadImage("Sponsoren.png");
  Produktion = loadImage("Produktion.png");
  Konstruktion = loadImage("Konstruktion.png");
}

void draw() {
  background(255);

  if ( state == 0 ) drawMainButtons(); 

  if ( state == 1 ) draw_back_button_and_some_text1();
  if ( state == 2 ) draw_back_button_and_some_text2();
  if ( state == 3 ) draw_back_button_and_some_text3();
  if ( state == 4 ) draw_back_button_and_some_text4();

  if ( state == 6 ) actOnFlag();
  if ( state == 7 ) {
   
    textSize(32);
    text("Das wars", 600, 150);
    text("Danke fürs mitmachen", 600, 200);
    draw_zurueck_button();
    index = 0;
    
  }
}

void mousePressed() {
  if ( state == 0 ) {
    if ( over(x1, y1, w1, h1) )  state = 1;
    if ( over(x2, y2, w2, h2) )  state = 2;
    if ( over(x3, y3, w3, h3) )  state = 3;
    if ( over(x4, y4, w4, h4) )  state = 4;
    if ( over(x6, y6, w6, h6) )  state = 6;
  } else {
    if ( state != 1 && state != 2 && state != 3 && state != 4){
    if ( over(x5, y5, w5, h5) )  state = 0;
    } else {

        if( over(x5, y5 + 100, w5 - 50, h5 - 50) ) state = 0;
 
    }
    
  }
    

  println("MouseX: " + mouseX + " MouseY: " + mouseY + " Flag: " + flag);

  //------------------------
  if (flag == 0) {
    if(state == 6){
    // Question 1
    if ( over(600, 500, 300, 300)) {     
      flag = 1;
    }
    if ( over(1000, 500, 300, 300)) {
      flag = 2;
    }
    }
  }
  //------------------------
  // Two result screens with a "Next button"
  else if (flag == 1) {
    // Correct 
    if (mouseX>600 && mouseX < 900 && mouseY >300 && mouseY <600) {
      flag = 3; // both proceed to Question 2
    }
  } else if (flag == 2) {
    // Wrong 
    if (mouseX>600 && mouseX < 900 && mouseY >300 && mouseY <600) {
      flag = 3; // both proceed to Question 2
    }
  } 
  //---------------------
  if (flag ==2 || flag == 1 || flag ==3) {
    if (mouseX>1316 && mouseX < 1366 && mouseY >0 && mouseY <50) {
      flag = 0;
    }//if
    //--------------------
    else {
      // flag = 0;
    }
    //
  }//func
  
}




void draw_back_button_and_some_text1() {
  background(Team);
  fill(0);
  //text("some text page1 ", 760, 50);
  //draw_zurueck_button();
  draw_low_zurueck_button();
}

void draw_back_button_and_some_text2() {
  background(Konstruktion);
  fill(0);
  //text("some text page2 ", 760, 50);
  //draw_zurueck_button();
  draw_low_zurueck_button();
}

void draw_back_button_and_some_text3() {
  background(Produktion);
  fill(0);
  //text("some text page3 ", 760, 50);
  //draw_zurueck_button();
  draw_low_zurueck_button();
}

void draw_back_button_and_some_text4() {
  background(Sponsoren);
  fill(0);
  //text("some text page4 ", 760, 50);
  //draw_zurueck_button();
  draw_low_zurueck_button();
}

void resultScreen() {
  if ((flag == 1 && correct[index] == 1) || (flag == 2 && correct[index] == 2)) {
    // Correct 
    pushStyle();
    background(255);
    fill(0, 255, 0);
    textSize(42);
    text("Richtig!", 600, 150);
    fill(0);
    rect(600, 300, 300, 300);
    textSize(32);
    fill(255);
    text("Nächste", 700, 400);
    text("Aussage->", 700, 450);

    draw_zurueck_button();

    popStyle();
  } else {
    // Wrong 
    pushStyle();
    background(255);
    fill(255, 0, 0);
    text("Falsch!", 600, 150);
    fill(0);
    rect(600, 300, 300, 300);
    textSize(32);
    fill(255);
    text("Nächste", 700, 400);
    text("Aussage->", 700, 450);

    draw_zurueck_button();

    popStyle();
  }
}//

boolean over(int x, int y, int w, int h) {
  return ( mouseX > x & mouseX < x + w   &&
    mouseY > y & mouseY < y + h      ) ;
}