DFPlayer mini + gets stuck in loop when it shouldnt.

#include "Arduino.h"
#include "SoftwareSerial.h"
#include "DFRobotDFPlayerMini.h"

const int buttonPin = 19;
int buttonState = 0;
int lastButtonState = 1;
long lastDebounceTime = 0;  // the last time the output pin was toggled
long debounceDelay = 5;    // the debounce time; increase if the output flickers

boolean doCompletionCheck = false;
int currentTrack = 0;

#define S_IDLE 1
#define S_POWERON 2
#define S_POWERDOWN 3
static int state = S_IDLE;

DFRobotDFPlayerMini myDFPlayer;
SoftwareSerial myDFPlayerSerialConn(7, 8);


void setup() {
  //debug (monitor)
  Serial.begin(115200);
  //talk to DFPlayer
  myDFPlayerSerialConn.begin(9600);
  
  Serial.println(F("Initializing DFPlayer ... (May take 3~5 seconds)"));
  if (!myDFPlayer.begin(myDFPlayerSerialConn)) {
    Serial.println(F("Unable to begin:"));
    Serial.println(F(" - Please recheck the connection!"));
    Serial.println(F(" - Please insert the SD card!"));
    while (true);
  }
  Serial.println(F("DFPlayer Mini online."));
  myDFPlayer.setTimeOut(500);
  myDFPlayer.volume(7);
  myDFPlayer.EQ(DFPLAYER_EQ_ROCK);
  myDFPlayer.outputDevice(DFPLAYER_DEVICE_SD);
    
  pinMode(buttonPin, INPUT);
  digitalWrite(buttonPin, HIGH);
  
  myDFPlayer.play(1);
  delay(2000);
}

void loop() {  
  switch (state) {
    case S_IDLE:
      buttonState = digitalRead(buttonPin);
      //if (buttonState != lastButtonState) {
      if ((buttonState != lastButtonState) && (millis() - lastDebounceTime > debounceDelay)) {
        lastDebounceTime = millis(); //update last time pressed/released
        
        if (buttonState == LOW) {  
          state = S_POWERON;
          
        }else {  
          state = S_POWERDOWN; 
          
        }    
      }else{        
        if(buttonState == LOW) {           
          if(currentTrack == 2 && doCompletionCheck == true){
            if(myDFPlayer.available()) {
              if(isFinished(myDFPlayer.readType(), myDFPlayer.read()) == 1){
              //if(isFinished(myDFPlayer.readType(), myDFPlayer.read()) == 1 && myDFPlayer.readState() != 513){
              //if(doCompletionCheck == true && currentTrack == 2 && myDFPlayer.readState() != 513 && isFinished(myDFPlayer.readType(), myDFPlayer.read()) == 1){
              //if(myDFPlayer.readState() != 513){
                Serial.println(F(">>> POWER ON PLAYBACK COMPLETE <<<"));                
                currentTrack = 3;
                doCompletionCheck = false;

                //myDFPlayer.stop();
                //myDFPlayer.disableLoop();
                //delay(10);//just a test!!!
                myDFPlayer.loop(3);
                //myDFPlayer.play(3);
                //myDFPlayer.next();
                //myDFPlayer.enableLoop();
              }              
            }
          }
                                      
        }else{                 
          if(currentTrack == 4 && doCompletionCheck == true){            
            if(myDFPlayer.available()) {                  
              if(isFinished(myDFPlayer.readType(), myDFPlayer.read()) == 1){                
                Serial.println(F(">>> POWER OFF PLAYBACK COMPLETE <<<"));                
                doCompletionCheck = false;                                 
              }              
            }
          }
        }       
      }
      lastButtonState = buttonState;
    break;

    

    case S_POWERON:
      Serial.println(F("[POWER UP]"));
      currentTrack = 2;      
      doCompletionCheck = true;
      //myDFPlayer.disableLoop();   
      myDFPlayer.play(2);
      //myDFPlayer.enableLoop();
      
      state = S_IDLE;
    break;

    

    case S_POWERDOWN:      
      Serial.println(F("[POWER DOWN]"));
      currentTrack = 4; 
      doCompletionCheck = true; 
      //myDFPlayer.disableLoop();
      myDFPlayer.play(4);
      //myDFPlayer.enableLoop();  //do not enable! 
      
      state = S_IDLE;    
    break;
  }

}

//used to check when a track is done playing
int isFinished(uint8_t type, int value) {
  switch (type) {   
    case DFPlayerPlayFinished:
      return 1;  
      break;
      
    //nothing            
    default:
      break;
  }
}