Problems sending messages with mkr Fox 1200

Hello, i am a noobie with this board, right now i have 2 soil sensors and one humidity and temperature sensor. the thing is i send messages to sigfox but just once when i upload the sketch i do not understand why the board do not send message every 15 minutes.

here is my code:

#include <SHT1x.h>
#define dataPin 10
#define clockPin 11
#include <SigFox.h>
#include <ArduinoLowPower.h>
SHT1x sht1x(dataPin, clockPin);
int oneshot = true;

const int analogInPinOnTheGround = A0;
int minADCground = 39;
int maxADCground = 895;

const int analogInPinUnderground = A4;
int minADCunderground = 60;
int maxADCunderground = 1000;

int moistureOnTheGroundValue, mappedOnTheGroundValue;

int moistureUndergroundValue, mappedUndergroundValue;

void setup() {
Serial.begin(115200);
delay(500);

if (oneshot == true) {
// Wait for the serial
Serial.begin(115200);
while (!Serial) {}
}

if (!SigFox.begin()) {
// Something is really wrong, try rebooting
// Reboot is useful if we are powering the board using an unreliable power source
// (eg. solar panels or other energy harvesting methods)
reboot();
}

//Send module to standby until we need to send a message
SigFox.end();

if (oneshot == true) {
// Enable debug prints and LED indication if we are testing
SigFox.debug();
}

}

void loop() {

// SENSOR A RAS DE SUELO
moistureOnTheGroundValue = analogRead(analogInPinOnTheGround);

Serial.print("ADC = " );
Serial.print(moistureOnTheGroundValue);
Serial.print(", " );

mappedOnTheGroundValue= map(moistureOnTheGroundValue,minADCground,maxADCground, 0, 100);

Serial.print("Moisture value on the ground = " );
Serial.print(mappedOnTheGroundValue);
Serial.println("%");

delay(2000);

//SENSOR ENTERRADO A 1.5 METROS DEL SUELO
moistureUndergroundValue = analogRead(analogInPinUnderground);

Serial.print("ADC = " );
Serial.print(moistureUndergroundValue);
Serial.print(", " );

mappedUndergroundValue= map(moistureUndergroundValue,minADCunderground,maxADCunderground, 0, 100);

Serial.print("Moisture value Underground (1.5 m) = " );
Serial.print(mappedUndergroundValue);
Serial.println("%");

delay(2000);

//SENSOR DE TEMPERATURA AMBIENTE Y HUMEDAD
float temp_c;
float temp_f;
float humidity;

// Read values from the sensor
temp_c = sht1x.readTemperatureC();
temp_f = sht1x.readTemperatureF();
humidity = sht1x.readHumidity();

// Print the values to the serial port
Serial.print("Temperature: ");
Serial.print(temp_c, DEC);
Serial.print("C / ");
Serial.print(temp_f, DEC);
Serial.print("F. Humidity: ");
Serial.print(humidity);
Serial.println("%");

delay(2000);

// Iniciamos el módulo SigFox
SigFox.begin();
// Esperamos 100 ms hasta que se conecte
delay(100);

// Limpieza de todas las interrupciones pendientes
SigFox.status();
delay(1);

// Comenzamos el proceso para transmitir el mensaje
SigFox.beginPacket();

// Escribimos el mensaje
SigFox.write(temp_c);
SigFox.write(humidity);
SigFox.write(mappedUndergroundValue);
SigFox.write(mappedOnTheGroundValue);

int ret = SigFox.endPacket(true); // send buffer to SIGFOX network and wait for a response
if (ret > 0) {
Serial.println("No transmission");
} else {
Serial.println("Transmission ok");
}

// Apagamos el módulo
SigFox.end();

if (oneshot == true) {
// spin forever, so we can test that the backend is behaving correctly
while (1) {}
}

//Sleep for 15 minutes
LowPower.sleep(15 * 60 * 1000);
}

void reboot() {
NVIC_SystemReset();
while (1);
}

this is my serial monitor:

ADC = 397, Moisture value on the ground = 41%
ADC = 393, Moisture value Underground (1.5 m) = 35%
Temperature: 24.8799972534C / 76.8559951782F. Humidity: 36.19%
No transmission

Always said no transmission but i can see the messages on sigfox.

Please help...

Sorry for my bad spelling and thank you for your help.

Hello,
try to turn the oneshoot flag to false, otherwise the program runs in the while(1) loop.
and another thing, two resistive soil sensors will disturb each other(the wet soil connect the GND of both sensors together), make sure you have disconnected them properly with a tristate output or similar.
hope it helps