Order of execution of print with pthreads in Linux

I'm using C and I want to get the String "ABCABCABCABCABCABC" in the output screen through multithreading, one thread does the 'A' character, another 'B' and the third one 'C'. If I compile the following code

#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>

#define cantidad_impresion_letra 6
pthread_mutex_t semaforo = PTHREAD_MUTEX_INITIALIZER;

void *escribirA(void *unused){
    int i;
    for(i=0;i<cantidad_impresion_letra;i++){
        pthread_mutex_lock(&semaforo);
        printf("A");
        pthread_mutex_unlock(&semaforo);
    }
}

void *escribirB(void *unused){
    int i;
    for(i=0;i<cantidad_impresion_letra;i++){
        pthread_mutex_lock(&semaforo);
        printf("B");
        pthread_mutex_unlock(&semaforo);
    }
}

void *escribirC(void *unused){
    int i;
    for(i=0;i<cantidad_impresion_letra;i++){
        pthread_mutex_lock(&semaforo);
        printf("C");
        pthread_mutex_unlock(&semaforo);
    }
}

int main(){
    pthread_t thread1, thread2, thread3;
    
    pthread_create(&thread1,NULL,escribirA,NULL);
    pthread_create(&thread2,NULL,escribirB,NULL);
    pthread_create(&thread3,NULL,escribirC,NULL);
        
    pthread_join(thread1, NULL);
    pthread_join(thread2, NULL);
    pthread_join(thread3, NULL);
    
    return(0);
}

on Windows through Dev-C++, the console throws me: ABACBACBACBACBACBC but if I compile THE SAME code in Linux, I get this: CCCCCCBBBBBBAAAAAA can someone explain me this pls? Btw, sorry for the uga-buga english