Different results while debbuging and without debbuging

Question

My code is the following:

#include <iostream>
#include <vector>
#include <ctime>
#include <algorithm> 

void printVector(const std::vector<int>& v) {
    std::cout << "[";
    for (int i = 0; i < v.size(); i++) {
        //cout << " The element " << i << " is " << v[i] << endl;
        if (i < v.size() - 1)
            std::cout << v[i] << ", ";
        else
            std::cout << v[i];
    }
    std::cout << "]" << std::endl << std::endl;
}


void chooseMainNumbers(std::vector<int>& mainNumbers)
{
    std::srand((unsigned int)(std::time(0)));
    std::random_shuffle(mainNumbers.begin(), mainNumbers.end());
    mainNumbers.resize(5); //getting mainNumbers to only have the first 5 numbers
}

void chooseLuckyStars(std::vector<int>& luckyStars)
{
    std::srand((unsigned int)(std::time(0)));
    std::random_shuffle(luckyStars.begin(), luckyStars.end());
    luckyStars.resize(2); //getting luckyStars to only have the first 2 numbers
}

void getIntersection(std::vector<int>& user, std::vector<int>& key)
{
    std::sort(user.begin(), user.end());
    std::sort(key.begin(), key.end());
    std::vector<int>::iterator it = std::set_intersection(user.begin(), user.end(), key.begin(), key.end(), user.begin());
    user.resize(it - user.begin());
}

int main()
{
    std::vector<std::vector<int>> userMainNumbers, userLuckyStars;
    std::vector<int> keyMainNumbers, keyLuckyStars;
    int N;
    std::cout << "Value of N? ";
    std::cin >> N;
    std::cout << std::endl;
    for (int i = 1; i <= N; i++)
    {
        std::vector<int> tempMainNumbers, tempLuckyStars;

        for (int j = 1; j <= 50; j++)
        {
            if (i == N)
            {
                if (j <=50)
                {
                    keyMainNumbers.push_back(j);
                }
                if (j <= 10)
                {
                    keyLuckyStars.push_back(j);
                }
            }
            if (j <= 50)
            {
                tempMainNumbers.push_back(j);
            }
            if (j <= 10)
            {
                tempLuckyStars.push_back(j);
            }
        }

        chooseMainNumbers(tempMainNumbers);
        chooseLuckyStars(tempLuckyStars);
        userMainNumbers.push_back(tempMainNumbers);
        userLuckyStars.push_back(tempLuckyStars);
        tempMainNumbers.clear();
        tempLuckyStars.clear();
    }

    chooseMainNumbers(keyMainNumbers);
    chooseLuckyStars(keyLuckyStars);
    std::cout << "Key main mumbers: ";
    printVector(keyMainNumbers);
    std::cout << "Key lucky Stars: ";
    printVector(keyLuckyStars);

    std::cout << "---------------------------------------------------------------------------" << std::endl << std::endl;

    for (int i = 0; i < userMainNumbers.size(); i++)
    {
        std::cout << i + 1 << " - Main mumbers: ";
        printVector(userMainNumbers[i]);
        getIntersection(userMainNumbers[i], keyMainNumbers);
        std::cout << "The intersection has: " << userMainNumbers[i].size() << " elements." << std::endl;
        printVector(userMainNumbers[i]);
        std::cout << i + 1 << " - Lucky Stars: ";
        printVector(userLuckyStars[i]);
        getIntersection(userLuckyStars[i], keyLuckyStars);
        std::cout << "The intersection has: " << userLuckyStars[i].size() << " elements." << std::endl;
        printVector(userLuckyStars[i]);
    }

    return 0;
}

I'm basically creating a program to simulate a EuroMillions bet, where I create N bets, where N is given by user, and then create a key, after that I compare all N bets with the key and print to the console the intersection from both. But I'm getting a error and can't figure it out. When I'm on debug mode the code will work right, but if I'm running it directly it will always give the same vector for userMainNumbers and keyMainNumbers / userLuckyStars and keyLuckyStars and consequently always give a perfect intersection.