Here is the simple sketch (LightSensor example) that I used. I added the #define MY_NODE_ID 15 line to force the node to broadcast a preset ID as not including this line led to the controller not logging any record of receiving the I_FIND_PARENT_REQUEST.

// Enable debug prints to serial monitor
#define MY_DEBUG
#define MY_RF24_PA_LEVEL RF24_PA_MAX
#define MY_NODE_ID 15

// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_NRF5_ESB
//#define MY_RADIO_RFM69
//#define MY_RADIO_RFM95

#include <MySensors.h>

#define CHILD_ID_LIGHT 25
#define LIGHT_SENSOR_ANALOG_PIN 0

//uint32_t SLEEP_TIME = 30000; // Sleep time between reads (in milliseconds)

MyMessage msg(CHILD_ID_LIGHT, V_LIGHT_LEVEL);
int lastLightLevel;


void presentation()
{
	// Send the sketch version information to the gateway and Controller
	sendSketchInfo("Light Sensor", "1.0");

	// Register all sensors to gateway (they will be created as child devices)
	present(CHILD_ID_LIGHT, S_LIGHT_LEVEL);
}

void loop()
{
	int16_t lightLevel = (1023-analogRead(LIGHT_SENSOR_ANALOG_PIN))/10.23;
	Serial.println(lightLevel);
	if (lightLevel != lastLightLevel) {
		send(msg.set(lightLevel));
		lastLightLevel = lightLevel;
	}
}

Here are the logs from the node:

 __  __       ____
|  \/  |_   _/ ___|  ___ _ __  ___  ___  _ __ ___
| |\/| | | | \___ \ / _ \ `_ \/ __|/ _ \| `__/ __|
| |  | | |_| |___| |  __/ | | \__ \  _  | |  \__ \
|_|  |_|\__, |____/ \___|_| |_|___/\___/|_|  |___/
        |___/                      2.3.2

16 MCO:BGN:INIT NODE,CP=RNNNA---,FQ=12,REL=255,VER=2.3.2
27 TSM:INIT
28 TSF:WUR:MS=0
35 TSM:INIT:TSP OK
38 TSM:FPAR
3353 ?TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
5363 !TSM:FPAR:NO REPLY
5364 TSM:FPAR
8680 ?TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
10689 !TSM:FPAR:NO REPLY
10690 TSM:FPAR
14006 ?TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
16016 !TSM:FPAR:NO REPLY
16018 TSM:FPAR
19334 ?TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
21344 !TSM:FPAR:FAIL
21345 TSM:FAIL:CNT=1
21348 TSM:FAIL:DIS
21349 TSF:TDI:TSL

and !TSM:FPAR:NO REPLY repeats over and over... But strangely these are the logs from the controller (Raspi running HA):

2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.transport] Receiving 0;255;3;0;9;20391 TSF:MSG:READ,15-15-255,s=255,c=3,t=7,pt=0,l=0,sg=0:
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.handler] n:0 c:255 t:3 s:9 p:20391 TSF:MSG:READ,15-15-255,s=255,c=3,t=7,pt=0,l=0,sg=0:
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.transport] Receiving 0;255;3;0;9;20398 TSF:MSG:BC
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.handler] n:0 c:255 t:3 s:9 p:20398 TSF:MSG:BC
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.transport] Receiving 0;255;3;0;9;20401 TSF:MSG:FPAR REQ,ID=15
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.handler] n:0 c:255 t:3 s:9 p:20401 TSF:MSG:FPAR REQ,ID=15
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.transport] Receiving 0;255;3;0;9;20404 TSF:PNG:SEND,TO=0
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.handler] n:0 c:255 t:3 s:9 p:20404 TSF:PNG:SEND,TO=0
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.transport] Receiving 0;255;3;0;9;20407 TSF:CKU:OK
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.handler] n:0 c:255 t:3 s:9 p:20407 TSF:CKU:OK
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.transport] Receiving 0;255;3;0;9;20410 TSF:MSG:GWL OK
2022-06-04 17:14:43 DEBUG (MainThread) [mysensors.handler] n:0 c:255 t:3 s:9 p:20410 TSF:MSG:GWL OK
2022-06-04 17:14:44 DEBUG (MainThread) [mysensors.transport] Receiving 0;255;3;0;9;21404 !TSF:MSG:SEND,0-0-15-15,s=255,c=3,t=8,pt=1,l=1,sg=0,ft=0,st=NACK:0
2022-06-04 17:14:44 DEBUG (MainThread) [mysensors.handler] n:0 c:255 t:3 s:9 p:21404 !TSF:MSG:SEND,0-0-15-15,s=255,c=3,t=8,pt=1,l=1,sg=0,ft=0,st=NACK:0

From the st=NACK:0, it seems that the node is not acknowledging the I_FIND_PARENT_RESPONSE.

I have already tried soldering a 100uF cap across the RF24 supply pins as well as powering the entire circuit using a lab bench power supply at 3.3V.
I find this extremely puzzling as the node can clearly establish a one-way communication line with the controller but not vice versa. Any help as to why this is happening would be greatly appreciated. Thanks.