If the main window has been minimized to the taskbar (iconified) calling "Show/Hide", "Send" or "Receive" actions from the tray icon menu has no effect: the main window still minimized.

It seems like a Qt bug similar to that old [one](https://bugreports.qt.io/browse/QTBUG-31117).

Tested platform: Linux Mint 19, Qt 5.9.5 / 5.9.6
{
    QString strTitle = tr("Bitcoin"); 
    
    int nMBoxIcon = QMessageBox::Information;
    int nNotifyIcon = Notificator::Information;
    QString msgType;
    
    if (!title.isEmpty()) {
        msgType = title;
    }
    else {
        switch (style) {
        case CClientUIInterface::MSG_ERROR:
            msgType = tr("Error");
            break;
        case CClientUIInterface::MSG_WARNING:
            msgType = tr("Warning");
            break;
        case CClientUIInterface::MSG_INFORMATION:
            msgType = tr("Information");
            break;
        default:
            break;
        }