DFPlayer Project - Please Help - Toy Car playing motor sound and triggered sound

I changed the code so that I can see where it gets stuck:

Seems like its looping 3x and then quits.

#include "Arduino.h"
#include "DFRobotDFPlayerMini.h"
unsigned long previousMillis = 0;  // will store last time LED was updated

// constants won't change:
const long interval = 5000;  // interval at which to blink (milliseconds)
DFRobotDFPlayerMini myDFPlayer;

void setup()
{
  Serial.println("setup");
  pinMode(0,INPUT);
  pinMode(1,INPUT);
  pinMode(2,INPUT);
  pinMode(3,INPUT);
  pinMode(4,INPUT);

  Serial.begin(115200);
  Serial1.begin(9600);
  myDFPlayer.begin(Serial1);
  myDFPlayer.volume(10); //set volume low
  delay(100); //wait another 100ms
  myDFPlayer.EQ(DFPLAYER_EQ_ROCK); //set EQ as pop
  delay(100); //wait another 100ms
  myDFPlayer.play(1);
  delay(3000);
}
void loop()
{   
      Serial.println("loop");
      unsigned long currentMillis = millis();
      if (digitalRead(0)== HIGH)
    {
      Serial.println("Werbung 1");
      myDFPlayer.advertise(1);
          }
     if (digitalRead(1)== HIGH)
    {
      Serial.println("Werbung 2");
      myDFPlayer.advertise(2);
          }
     if (currentMillis - previousMillis >= interval) {
    // save the last time you blinked the LED
    previousMillis = currentMillis;
    myDFPlayer.play(2);
    }    

17:32:24.021 -> loop

17:32:24.021 -> loop

17:32:24.021 -> Werbung 2

17:32:24.021 -> loop

17:32:24.021 -> Werbung 2

17:32:24.021 -> loop

17:32:24.021 -> Werbung 2