Is this a memory leak or am I misreading what Visual Studio 2017 is showing? - allegro5

Question

I am just learning C++ and figured to use Allegro 5 and Visual Studio 2017 to make a simple 2D game but having written a very simple program that just creates and destroys a window, I am worried that there is a memory leak when so far as I am aware, the code should be fine in this regard.
Hopefully, I just need to understand better what Visual Studio is showing me when running the code via the 'Local Windows Debugger' option.
I'm running the code below via Visual Studio 2017 and the 'Local Windows Debugger' option.
The code runs fine so far as I can see but in the 'Diagnostic Tools' window, looking at Process Memory usage, I am concerned there might be a memory leak.
Here is the code...
#include <iostream>
#include <allegro5/allegro5.h>
int main()
{
std::system ("pause");
al_init();
ALLEGRO_DISPLAY *disp = al_create_display(320, 200);
std::system ("pause");
al_destroy_display(disp);
std::cout << "allegro display has been destroyed...\n";
std::system("pause");
return 0;
}
You'll see I have inserted pauses at various places in the code, and when the code reaches the last Pause, I am expecting Process Memory usage to be the same as when the code was at the first Pause.
Meaning that I am expecting Process Memory usage to be the same at the end of main, as it is at the start, or certainly after al_init();
But what I see is...
Typically the Process Memory shows usage of...
At start of Main... 1.7MB
After al_init();... 1.7MB
After creating display/window... 31.4MB
After al_destroy display/window... 13.8MB
Surely after the window is destroyed/closed I should see Process Memory usage return to 1.7MB?
I created a similarly simply program using OpenGL and see similar behavior albeit with higher Process Memory usage in general.
Hopefully, I just need to understand better what Visual Studio is showing me when running the code via the 'Local Windows Debugger' option.
Thank you for reading....