Cannot show green tick icons on empty folder(placeholder file)

[WebsocketUser]

I use the following code to convert local empty folder to place holder file, and set pin state to CF_PIN_STATE_UNSPECIFIED, but the empty folder icon always showed unpinned state.
Windows SDK:10.0.22621.0
Here also post the issue:https://docs.microsoft.com/en-us/answers/questions/987093/set-empty-folder-with-unspecified-state-icon.html

CString strFolderPath = L"C:\Users\admin\SyncFolder\emptyfolder\";
CString strFolderName = L"emptyfolder";
HRESULT hr = CfOpenFileWithOplock(strFolderPath , CF_OPEN_FILE_FLAG_EXCLUSIVE, &ProtectedHandle);
if (SUCCEEDED(hr))
{
hr = CfConvertToPlaceholder(
ProtectedHandle,
strFolderName.GetBuffer(),
(USHORT)(strFolderName.GetLength() + 1) * sizeof(WCHAR),
CF_CONVERT_FLAG_MARK_IN_SYNC,
nullptr,
NULL);
CfCloseHandle(ProtectedHandle);
strFolderName.ReleaseBuffer();
if (SUCCEEDED(hr))
{
HANDLE hFile = ::CreateFile(strFolderPath , 0, FILE_READ_DATA, nullptr, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, nullptr);
if (hFile != INVALID_HANDLE_VALUE)
{
hr = CfSetPinState(hFile, CF_PIN_STATE_UNSPECIFIED, CF_SET_PIN_FLAG_NONE, NULL);
::CloseHandle(hFile);
}
}
}