MacOS ignore keyevent filters

[RazrFalcon]

I need to prevent entering non HEX symbols into QLineEdit, but default setInputMask work not really good for me.
So I tried to write it by myself:
@bool LineEdit::eventFilter(QObject *obj, QEvent *event)
{
if (obj == this) {
if (event->type() == QEvent::KeyPress)
{
QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
if (!keyEvent->text().contains(QRegExp("[^a-fA-F0-9]")) && !keyEvent->text().isEmpty())
// bruteforce way
// if (keyEvent->key() == Qt::Key_A
// || keyEvent->key() == Qt::Key_B
// || keyEvent->key() == Qt::Key_C
// || keyEvent->key() == Qt::Key_D
// || keyEvent->key() == Qt::Key_E
// || keyEvent->key() == Qt::Key_F
// || keyEvent->key() == Qt::Key_0
// || keyEvent->key() == Qt::Key_1
// || keyEvent->key() == Qt::Key_2
// || keyEvent->key() == Qt::Key_3
// || keyEvent->key() == Qt::Key_4
// || keyEvent->key() == Qt::Key_5
// || keyEvent->key() == Qt::Key_6
// || keyEvent->key() == Qt::Key_7
// || keyEvent->key() == Qt::Key_8
// || keyEvent->key() == Qt::Key_9)
{
this->setText(this->text() + keyEvent->text().toUpper());
return true;
} else {
return true;
}
}
}
return QLineEdit::eventFilter(obj, event);
}@

On Linux all works fine, but on Mac I can enter cyrillic symbols. And I can't prevent it in any ways.
And any of methods I trying, can't prevent it.

Is it Mac bug?

Here is minimal compilable example:
http://rghost.ru/download/41304261/a1f3826a4a0964e3446e24554f63f95082e4e6c8/keyevent-test.zip