Calls to GetLoginItemSettings (amonst others) will get GetAppUserModelId which will implicit set a new one if there hasn't been a user defined one yet.  This causes an issue in a UWP environment where the AppUserModelId is system defined.

On the latest versions of windows the AppUserModelId defined for your notification must match exactly the one defined for your process or no notification will appear.  Got a fix in the works for this just raising here for tracking purposes.
brightray/browser/win/windows_toast_notification.cc
IXmlDocument* doc,
                                               IXmlNodeList** node_list,
                                               uint32_t req_length) {
  tag->Reset(L"text");
  if (!tag->success())
    return false;
  if (FAILED(doc->GetElementsByTagName(*tag, node_list)))
    return false;
  uint32_t node_length;
  if (FAILED((*node_list)->get_Length(&node_length)))
    return false;
  return node_length >= req_length;
}
bool WindowsToastNotification::AppendTextToXml(IXmlDocument* doc,
                                               IXmlNode* node,
                                               const std::wstring& text) {
  ScopedHString str(text);
  if (!str.success())
    return false;
  ComPtr<IXmlText> xml_text;
  if (FAILED(doc->CreateTextNode(str, &xml_text)))
    return false;
  ComPtr<IXmlNode> text_node;
  if (FAILED(xml_text.As(&text_node)))
    return false;
  ComPtr<IXmlNode> append_node;
  return SUCCEEDED(node->AppendChild(text_node.Get(), &append_node));
}
bool WindowsToastNotification::SetupCallbacks(