QueryDosDeviceW returns 0 when called from a source other than the main thread. Why?
I used Visual Studio 2022 (v143) platform.
Below is the test code and output.

#include <iostream>
#include <string>
#include <vector>
#include <thread>
#include <chrono>
#include <fileapi.h>

std::vector<std::string> GetAvailableSerialPortsNames() {
  std::vector<std::string> com_names;
  TCHAR lp_target_path[5000];
  for (int i = 0; i <= 255; i++) { // checking ports from COM0 to COM255
    std::string com_name = "COM" + std::to_string(i); // converting to COM0, COM1, COM2
    DWORD Test 
      = QueryDosDeviceW((LPCWSTR)(
        std::wstring(com_name.begin(), com_name.end()).c_str()), 
        (LPWSTR)lp_target_path, 5000);
    if (Test != 0)
      com_names.push_back(com_name);
    if (::GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
      lp_target_path[10000]; // in case the buffer got filled, increase size of the buffer.
      continue;
    }
  }
  return com_names;
}

int main(void) {
  auto serials = GetAvailableSerialPortsNames();
  std::cout << "Querying in main thread. Ports count=" << serials.size() << std::endl;
  for (auto s : serials) std::cout << s << std::endl;

  std::thread([]() {
    auto serials = GetAvailableSerialPortsNames();
    std::cout << "Querying in other thread. Ports count=" << serials.size() << std::endl;
    for (auto s : serials) std::cout << s << std::endl;
  }).detach();
  
  std::this_thread::sleep_for(std::chrono::seconds(3));

  return 0;
}

Querying in main thread. Ports count=3
COM1
COM3
COM4
Querying in other thread. Ports count=0