thanks @fets have I specified the wait time at the wrong location? In the sketch below, everything works, BUT the PIR triggers 0 over and over and over again.....
 #define MY_GW_ID 50
// Enable debug prints
#define MY_DEBUG
// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69
#include <SPI.h>
#include <MySensor.h>  
#include <DHT.h>  
#include <Bounce2.h>
//Constants
#define SKETCH_NAME           "3 in 1 Sensor"
#define SKETCH_VERSION        "1.0"
#define CHILD_ID_TEMP 11                  // Child id for Temperature
#define CHILD_ID_HUM 10                   // Child id for Humidity
#define CHILD_ID_MOT 2                   // Child id for Motion
#define HUMIDITY_SENSOR_DIGITAL_PIN 7    // Where is my DHT22 data pin connected to
#define DIGITAL_INPUT_SENSOR 3           // The digital input you attached your motion sensor.  (Only 2 and 3 generates interrupt!)
#define INTERRUPT DIGITAL_INPUT_SENSOR-2 // Usually the interrupt = pin -2 (on uno/nano anyway)
#define CHILD_ID_SW 3                    // Child id for Reed Switch
#define BUTTON_PIN  2                    // Arduino Digital I/O pin for button/reed switch
#define RELAY_1  4  // Arduino Digital I/O pin number for first relay (second on pin+1 etc)
#define NUMBER_OF_RELAYS 1 // Total number of attached relays
#define RELAY_ON 1  // GPIO value to write to turn on attached relay
#define RELAY_OFF 0 // GPIO value to write to turn off attached relay
int node_id=50;                          // What is my node id
MySensor gw;
Bounce debouncer = Bounce(); 
int oldValue=-1;
DHT dht;
//Store last values
float lastTemp = 0 ;                  
float lastHum = 0 ;
;             
boolean lastTripped = false ;
boolean metric = true; 
boolean gwsend = true;              // to determine if data has to be sent
MyMessage msgHum(CHILD_ID_HUM, V_HUM);
MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);
MyMessage msgMot(CHILD_ID_MOT, V_TRIPPED);
MyMessage msgsw(CHILD_ID_SW,V_TRIPPED);
void setup()  
{ 
  gw.begin(NULL,node_id,false);
  gw.wait(5);
  dht.setup(HUMIDITY_SENSOR_DIGITAL_PIN); 
  // Send the Sketch Version Information to the Gateway
  gw.sendSketchInfo("3 in 1 Sensor", "1.0",true);
 //  - NEW Setup the button
 
  pinMode(BUTTON_PIN,INPUT);
  // Activate internal pull-up
  digitalWrite(BUTTON_PIN,HIGH);
  
  // After setting up the button, setup debouncer
  debouncer.attach(BUTTON_PIN);
  debouncer.interval(5);
 //  - NEW Setup the button END
pinMode(DIGITAL_INPUT_SENSOR, INPUT);      // sets the motion sensor digital pin as input
 
  // Register all sensors to gw (they will be created as child devices)
  gw.present(CHILD_ID_HUM, S_HUM,"Garage Humidity");
  gw.present(CHILD_ID_TEMP, S_TEMP,"Garage Temperature");
  gw.present(CHILD_ID_SW, S_DOOR,"Garage Door");
  metric = gw.getConfig().isMetric;
}
void loop()      
  // Read Reed switch value
{
  debouncer.update();
  // Get the update value
  int value = debouncer.read();
 
  if (value != oldValue) {
     // Send in the new value
     gw.send(msgsw.set(value==HIGH ? 1 : 0));
     oldValue = value;
  }
  // Read Temp - Humidity Value
{  
  delay(dht.getMinimumSamplingPeriod());
  float temperature = dht.getTemperature();
  if (isnan(temperature)) {
      Serial.println("Failed reading temperature from DHT");
  } else if (temperature != lastTemp) {
    lastTemp = temperature;
    if (!metric) {
      temperature = dht.toFahrenheit(temperature);
    }
    gw.send(msgTemp.set(temperature, 1));
    Serial.print("T: ");
    Serial.println(temperature);
  }
  
  float humidity = dht.getHumidity();
  if (isnan(humidity)) {
      Serial.println("Failed reading humidity from DHT");
  } else if (humidity != lastHum) {
      lastHum = humidity;
      gw.send(msgHum.set(humidity, 1));
      Serial.print("H: ");
      Serial.println(humidity);
  }
{     
  // Read digital motion PIR value
  boolean tripped = digitalRead(DIGITAL_INPUT_SENSOR) == HIGH;
   
        
  Serial.println(tripped);
  gw.send(msgMot.set(tripped?"1":"0"));  // Send tripped value to gw 
  }
}
}
Thanks