nrf24l01 radio not available even with two capacitors soldered on

I used the code from here: https://forum.arduino.cc/index.php?topic=421081.0
with the only difference that I put radio.setAutoAck(false); after radio.begin() as per suggestion of another video.

// SimpleTx - the master or the transmitter

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>


#define CE_PIN   9
#define CSN_PIN 10

const byte slaveAddress[5] = {'R','x','A','A','A'};


RF24 radio(CE_PIN, CSN_PIN); // Create a Radio

char dataToSend[10] = "Message 0";
char txNum = '0';


unsigned long currentMillis;
unsigned long prevMillis;
unsigned long txIntervalMillis = 1000; // send once per second


void setup() {

    Serial.begin(9600);

    Serial.println("SimpleTx Starting");

    radio.begin();
    radio.setAutoAck(false); 
    radio.setDataRate( RF24_250KBPS );
    radio.setRetries(3,5); // delay, count
    radio.openWritingPipe(slaveAddress);
}

//====================

void loop() {
    currentMillis = millis();
    if (currentMillis - prevMillis >= txIntervalMillis) {
        send();
        prevMillis = millis();
    }
}

//====================

void send() {

    bool rslt;
    rslt = radio.write( &dataToSend, sizeof(dataToSend) );
        // Always use sizeof() as it gives the size as the number of bytes.
        // For example if dataToSend was an int sizeof() would correctly return 2

    Serial.print("Data Sent ");
    Serial.print(dataToSend);
    if (rslt) {
        Serial.println("  Acknowledge received");
        updateMessage();
    }
    else {
        Serial.println("  Tx failed");
    }
}

//================

void updateMessage() {
        // so you can see that new data is being sent
    txNum += 1;
    if (txNum > '9') {
        txNum = '0';
    }
    dataToSend[8] = txNum;
}
// SimpleRx - the slave or the receiver

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>

#define CE_PIN   9
#define CSN_PIN 10

const byte thisSlaveAddress[5] = {'A','B','C','D','E'};

RF24 radio(CE_PIN, CSN_PIN);

char dataReceived[10]; // this must match dataToSend in the TX
bool newData = false;

//===========

void setup() {

    Serial.begin(9600);

    Serial.println("SimpleRx Starting");
    radio.begin();
    radio.setAutoAck(false); 
    radio.setDataRate( RF24_250KBPS );
    radio.openReadingPipe(1, thisSlaveAddress);
    radio.startListening();
}

//=============

void loop() {
    getData();
    showData();
}

//==============

void getData() {
    if ( radio.available() ) {
        radio.read( &dataReceived, sizeof(dataReceived) );
        newData = true;
    }
}

void showData() {
    if (newData == true) {
        Serial.print("Data received ");
        Serial.println(dataReceived);
        newData = false;
    }
}

Photos of the circuit is here: https://photos.app.goo.gl/kwWG59hL482DdTm39

When the code is put in, Simple Tx runs fine on either board and the serial reads this continuously:

SimpleTx Starting
Data Sent Message 0  Acknowledge received
Data Sent Message 1  Acknowledge received
Data Sent Message 2  Acknowledge received
Data Sent Message 3  Acknowledge received
Data Sent Message 4  Acknowledge received
Data Sent Message 5  Acknowledge received
Data Sent Message 6  Acknowledge received
Data Sent Message 7  Acknowledge received
Data Sent Message 8  Acknowledge received
Data Sent Message 9  Acknowledge received
Data Sent Message 0  Acknowledge received
Data Sent Message 1  Acknowledge received
Data Sent Message 2  Acknowledge received
Data Sent Message 3  Acknowledge received
Data Sent Message 4  Acknowledge received
Data Sent Message 5  Acknowledge received
Data Sent Message 6  Acknowledge received

However on either board, simple rx’s serial is stuck on
SimpleRx Starting
and never goes to the radio.
(That is, if I use this code where I check to see if radio is available or not:)

// SimpleRx - the slave or the receiver

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>

#define CE_PIN   9
#define CSN_PIN 10

const byte thisSlaveAddress[5] = {'A','B','C','D','E'};

RF24 radio(CE_PIN, CSN_PIN);

char dataReceived[10]; // this must match dataToSend in the TX
bool newData = false;

//===========

void setup() {

    Serial.begin(9600);

    Serial.println("SimpleRx Starting");
    radio.begin();
    radio.setAutoAck(false); 
    radio.setDataRate( RF24_250KBPS );
    radio.openReadingPipe(1, thisSlaveAddress);
    radio.startListening();
}

//=============

void loop() {
    getData();
    showData();
}

//==============

void getData() {
    if (!radio.available()){
      Serial.println("not available");
    }
    if ( radio.available() ) {
        radio.read( &dataReceived, sizeof(dataReceived) );
        newData = true;
    }
}

void showData() {
    if (newData == true) {
        Serial.print("Data received ");
        Serial.println(dataReceived);
        newData = false;
    }
}

I get
not available
not available
not available
not available
not available
not available
continuously

The modules are not getting hot

Oh it suddenly works again. I have no idea why but it works sometimes and doesn't work other times?

Edit: All I did was upload the ackpayload one from Robin2 then reupload the simple one. I have no idea what changed.

Edit2: This worked before too without the capacitors and I can't tell if the capacitors are making a difference. What could have gone wrong?

When you reset an Arduino it does not reset the nRF24. The only way to reset the nRF24 is by disconnecting power from it. You may have done that without being conscious of its significance in the course of your tests.

Fast repetition of a message usually means the Arduino is not connecting properly with its own nRF24.

Use the connection-test program in my tutorial to check that the Arduino can talk to the nRF24 connected to to it.

...R