ESP8266 - Problem with LittleFS after reboot (solved in comments)

Question

I'm trying to create an even log saved on flash. I try to make it a class, called flashLOG as shown. Code behaves as expceted, reads, writes and posts it size and entries.

The problem is that after reboot - it seems that the file "disappears".

Code is written based on the Arduino IDE example. First I thought it is a flash problem, but after flashing Arduino's example and tried to run my code on an other MCU - it seems there no physical problem with flash.

I tried to reduce most of my code only to write "events" in order to see what survives reboot - so please ignore commented out lines and some logic in reading text, in code attached.

The only thing came in mind- perhaps it has something to do with being in a class or inside a library.

Appreciate any help finding this bug **EDIT 1: ** Update .h file and .ino fil

.h file

class flashLOG {
private:
    char *_logfilename = "/logfile.txt";
    const static int _logsize = 5;     // entries
    const static int _log_length = 20; // chars in each entry
    char _log_array[_logsize][_log_length];
public:
    flashLOG(char *filename = "/logfile.txt");
    void start();
    void read();
    void write(const char *message);
    void append(const char *message);
    void postlog(int x);
    int sizelog();
};

.cpp file:

flashLOG::flashLOG(char *filename) 
{
    _logfilename = filename;
}
void flashLOG::start() {
    if (!LittleFS.begin())
    {
        Serial.println("LittleFS mount failed");
    }
    else {
        Serial.println("MOUNTED OK");
    }
}
void flashLOG::read() {
    int r = 0;
    int c = 0;

    File file = LittleFS.open(_logfilename, "r");
    if (!file)
    {
        Serial.println("Failed to open file for reading");
    }
    else {
        while (file.available())
        {
            char tt = file.read();
            //     if (tt != '\n')
            //     {
            //         _log_array[r][c] = tt;
            //         c++;
            //     }
            //     else
            //     {
            //         _log_array[r][c] = '\n';
            //         r++;
            //         c = 0;
            //         // Serial.println(_log_array[r-1]);
            //     }
            Serial.write(tt);
        }
    }
    file.close();
    //     return r;

}
void flashLOG::write(const char *message)
{
    char a[_log_length];
    //     sprintf(a, "%s\n", message);

    File file = LittleFS.open(_logfilename, "a");
    if (!file)
    {
        Serial.println("Failed to open file for appending");
    }
    else {
        if (file.print(message)) {
            Serial.println("Append OK");
        }
        else {
            Serial.println("Append fail");
        }
    }
    Serial.printf("file size: %d\n", file.size());
    delay(2000);
    file.close();
}
void flashLOG::append(const char *message)
{
    char a[_log_length];
    //     sprintf(a, "%s\n", message);

    File file = LittleFS.open(_logfilename, "a");
    if (!file)
    {
        Serial.println("Failed to open file for appending");
    }
    else {
        if (file.print(message)) {
            Serial.println("Append OK");
        }
        else {
            Serial.println("Append fail");
        }
    }
    Serial.printf("file size: %d\n", file.size());
    //     delay(2000);
    file.close();
}
void flashLOG::postlog(int x)
{
    int num_lines = 0;//read();
    int y = min(x, num_lines);
    for (int a = 0; a < y; a++)
    {
        if (y > 1)
        {
            char t[_log_length];
            sprintf(t, "[#%d] %s", a, _log_array[a]);
            Serial.println(t);
        }
        else
        {
            Serial.println(_log_array[a]);
        }
    }
}
int flashLOG::sizelog()
{
    File file = LittleFS.open(_logfilename, "r");
    int f=file.size();
    file.close();
    return f;
}

.ino file

#include <myIOT.h>
#include <Arduino.h>

flashLOG flog;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  Serial.println("\nBEGIN!");
  flog.start();
//  flog.write("HITHERE");
  flog.read();
  flog.append("HITHERE2");
//  flog.read();

}

void loop() {
  // put your main code here, to run repeatedly:

}