Random number generator with a time seed is not working [duplicate]

This question already has an answer here:

• Why do I always get the same sequence of random numbers with rand()? 12 answers

So I'm practicing classes and headers. I'm trying to create a simpler random number generator by putting it into another class. The source code compiles without any errors. However, as you can see in the source code I use time(0) as a seed to generate random numbers. Yet somehow the seed doesn't change when I restart the program multiple times to test the randomness. The seed is apparently the same. Why is this ?

---

main.cpp

 #include <iostream>
 #include "RandomNumber.h"

 using namespace std;

 int main(){

    RandomNumber rand;
    int a = 10000;
    int randomnumber = rand.RandNumGen(1, 100);

    cout << "10 000 - a random number between 1 and 100 looks like this\n" << a << " - " << randomnumber << " = " << a - randomnumber << endl;
 return 0;
 }

---

RandomNumber.h

 #include <iostream>
 #include <ctime>
 #include <random>

 using namespace std;



 class RandomNumber
{
public:
    RandomNumber();
    int RandNumGen(int minimum, int maximum);

protected:

private:
};

#endif

---

RandomNumber.cpp

 #include "RandomNumber.h"

 using namespace std;

 RandomNumber::RandomNumber(){

 }

 int RandomNumber::RandNumGen(int minimum, int maximum){

 default_random_engine generator(time(0));

 uniform_int_distribution<int> RNG(minimum, maximum);

 return RNG(generator);
 }

In short. The RandNumGen function in the RandomNumber class returns the same random number even though the seed is constantly changing (using time in seconds).