Arduino GSM Shield returning Numbers not Text; HEX PDU not CHAR or empty message

I’m trying to receive messages from SIM900 GSM shield on an Arduino through the Serial Monitor on Linux: I can send and received messages, without a problem.

The problem I have is that the received message is outputted as PDU instead of text, although it has been set with AT+CMGF=1 , when I AT+CMGF? it returns 1.

This is the sample code from sketch:

#include <SoftwareSerial.h>
SoftwareSerial SIM900(7, 8);
 
char incoming_char=140;
 
void setup()
{
  Serial.begin(19200); // for serial monitor
  SIM900.begin(19200); // for GSM shield
  SIM900power();  // turn on shield
  delay(20000);  // give time to log on to network.
 
  SIM900.println("AT+CMGF=1");  // set SMS mode to text
  delay(100);
  SIM900.println("AT+CNMI=2,2,0,0,0");
  // blurt out contents of new SMS upon receipt to the GSM shield's serial out
  delay(100);
}
 
void SIM900power()
// software equivalent of pressing the GSM shield "power" button
{
  digitalWrite(9, HIGH);
  delay(1000);
  digitalWrite(9, LOW);
  delay(7000);
}
 
void loop()
{
  // Now we simply display any text that the GSM shield sends out on the serial monitor
  if(SIM900.available() >0)
  {
    incoming_char=SIM900.read(); //Get the character from the cellular serial port.
    Serial.println(incoming_char); //Print the incoming character to the terminal.
  }
}

And this is the output from serial monitor:

AT+CMGF=1

OK

AT+CNMI=2,2,0,0,0

OK

When I SMS a message to the shield this appears, as the message:

+CMT: “2B38363138363435313939303330”,"",“15/01/30,13:51:27+32”
546869732069732061206D6573736167652E

This is the decoded PDU:

SMSC#
Sender:37029637021602D6563737167656E2

TimeStamp:// ::
TP_PID:
TP_DCS:
TP_DCS-popis:Uncompressed Text
class:0
Alphabet:Default

Length:0

Could it be the message is empty? How would I solve this? Any Help is appreciated.

SoftwareSerial SIM900(7, 8);

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