Arduino IDE missing timestamps on serial monitor

[Rocketct]

Hi all, the 1.8.7 version of the IDE doesn't show the timestamp in each line when the following sketch is running on a MKRGSM board:

#include <MKRGSM.h>

const char PINNUMBER[]     = "";
const char GPRS_APN[]      = "Your_APN";
const char GPRS_LOGIN[]    = "";
const char GPRS_PASSWORD[] = "";

GSMClient client;
GPRS gprsAccess;
GSM gsmAccess(true);

String response = "";
String okmsg = "ok";
String errormsg = "error";

void setup() {
  delay(3000);

  Serial.begin(115200);
  int i;
  //setted a timeout of 180 s for the GPRS and GSM operation
  gprsAccess.setTimeout(30000);
  gsmAccess.setTimeout(30000);
  for (i = 0; i < 5; i++) {
    Serial.print("Connecting GSM network...");
    if ((gsmAccess.begin() != GSM_READY) &&
        (gprsAccess.attachGPRS(GPRS_APN, GPRS_LOGIN, GPRS_PASSWORD) != GPRS_READY)) {

      Serial.println("error");
      Serial.println(i);
    } else {
      Serial.println("connected");
      break;
    }
    delay(1000);

    if (gsmAccess.status() != GSM_READY) {
        Serial.println("loop");
      while (true);
    }
  }
}

void loop() {

  Serial.println("Connecting GSM network...");

  if (Serial) Serial.println("Attaching to GPRS with your APN...");
  if ((gsmAccess.begin() != GSM_READY) &&
      (gprsAccess.attachGPRS(GPRS_APN, GPRS_LOGIN, GPRS_PASSWORD) != GPRS_READY)) {
    Serial.println("error");
  } else {
    Serial.println("connected");

  }

  gsmAccess.shutdown();
  Serial.println("sleeping");


  delay(10000);
}

A portion of the serial monitor where the issue occur is reported following:

11:28:57.813 -> +CREG: 0,0
11:28:57.813 -> 
11:28:57.813 -> OK
AT+CREG?

11:28:58.013 -> +CREG: 0,5
11:28:58.013 -> 
11:28:58.013 -> OK
AT+UCALLSTAT=1

11:28:58.212 -> OK
11:28:58.212 -> connected
AT+CPWROFF

11:29:03.899 -> OK
11:29:03.899 -> sleeping
Connecting GSM network...
11:29:13.905 -> Attaching to GPRS with your APN...
⸮AT

11:29:17.992 -> OK
AT+IPR=921600

11:29:18.025 -> OK

[aravindnadumane]

Why not use external Tools for Serial monitoring like: https://hiterminallogger.sourceforge.io/