Unwanted shut down of outputs.

Projects Programming
7

The code does debouncing with a delay of 10ms, but then uses the button state to set the LEDs directly, so they will only be on with the button is pressed (and upto 10ms afterwards due to the debounce delay).

You want the button being active to toggle the state, something like

  if (val != buttonState)
  {
    buttonState = val ;
    if (!val)  // button was pressed
      ledState = !ledState ; // toggle
    digitalWrite(LED1, ledState);
    digitalWrite(LED2, ledState);
    digitalWrite(LED3, ledState);
    digitalWrite(LED4, ledState);
    digitalWrite(LED5, ledState);
  }

Using an array of pin numbers will make the code less voluminous!