Process ID changes when program is visible or minimized

I am trying to get the Process ID of a program (PID) but for some odd reason, the PID changes. When the target program (Alarms & Clock) is visible, it gives me the wrong PID while having the program minimized gives me the right PID.

I am guessing that minimizing the target program suspends it's process, thus allowing it to be read. However, simply reading the PID should not be a restriction even when a process is running.

Does anyone have an idea on what am I doing wrong?

Currently Tried Methods:

• Ran in Administrative Mode
• Compiled for 64 bit
• Compiled for 32 bit

ere is a working, concise piece of code that portrays the problem:

#include <iostream>
#include <Windows.h>
#include <string>

int main()
{
    std::string window_name = "Alarms & Clock"; //Feel free to replace this with another program
    HWND hwnd = FindWindowA(NULL, window_name.c_str());
    if (!hwnd)
    {
        std::cerr << "Error: Could not find window" << std::endl;
        return -1;
    }

    DWORD processID = 0;
    GetWindowThreadProcessId(hwnd, &processID);
    std::cout << "Process ID: " << processID << std::endl;
    std::cin.get();

    return 0;
}