Communication between two Arduinos through nRF24L01 module stops after a while

Using Arduino Programming Questions
#1

I have a simple communication between two Arduinos.
Transmitter sends data, receiver receives it and controls a relay, simple. This proccess stops after some hours of working perfectly.

Resetting the transmitter or the receiver solves the problem temporarily, but that’s not a true solution.

Both Arduinos are powered the same way: through a 220V transformers (USB cable) with output 5V and 2.4A. I suppose that’s ok as the project works for hours.

Would it be a memory leak? I will post transmitter’s and receiver’s code.

Transmitter’s code:

#include <SPI.h>
#include <RF24.h>
RF24 radio(7,8);
const byte address = "00001";

void setup() {
  pinMode(2, INPUT_PULLUP);
  Serial.begin(9600);
  radio.begin();
  radio.openWritingPipe(address);
  radio.setPALevel(RF24_PA_LOW);
  radio.stopListening();
 }

void loop() {
  const char text[] = "porta";
  radio.write(&text, sizeof(text));
  delay(20000);
 }

Receiver’s code:

#include <SPI.h>
#include <RF24.h>
RF24 radio(7,8);
const byte address = "00001";

void setup() {
pinMode(4, OUTPUT); //relay
digitalWrite(4, LOW); //relay
Serial.begin(9600);
radio.begin();
radio.openReadingPipe(0, address);
radio.setPALevel(RF24_PA_LOW);
radio.startListening();

}

void loop() {

if(radio.available()) {

char text[32] = "";
radio.read(&text, sizeof(text));
Serial.println(text);

digitalWrite(4, LOW);
delay(100);
digitalWrite(4, HIGH);
delay(100);
digitalWrite(4, LOW);
delay(100);
digitalWrite(4, HIGH);
delay(1000);
}
}
#2