In line 52 please change
// Turns off all the LEDs
for (int i = 0; i < 5; i++) {
digitalWrite(LEDpins[0], LOW);
}
to
// Turns off all the LEDs
for (int i = 0; i < 5; i++) {
digitalWrite(LEDpins[i], LOW);
}
which is actually fixing a typo: I was turning off 5 times the LED on the first pin in the pins array rather than turning off once all the pins in the same array.
That should fix your issue. Not related to RF24 though