Scroll String Only On Second Line Using 2x16 LCD
You need to reset the stringStart, stringStop and scrollCursor at the beginning of the roop function.

void roop(String line1, String line2) {

  countMovement = 0;
  stringStart = 0;
  stringStop = 0;
  scrollCursor = screenWidth;

  ...


I think you also need to move the lcd.clear up. Or else the screen will be blanked when the roop function is done scrolling.

...

  while ( ( countMovement ) &lt; (line2.length() + screenWidth )  ) {

     lcd.clear();
     lcd.setCursor(scrollCursor, 1);
     lcd.print(line2.substring(stringStart,stringStop));
     lcd.setCursor(4, 0); // 1 = word eat array of words very cool
     lcd.print(line1);
     delay(300);

...