Signal textChanged(QString) does not emit from QLineEdit in new Qt.

In my Android app I use QLineEdit attached to QGraphicsProxyWidget laying on QGraphicsScene. I connect QLineEdit::textChanged(QString) signal for some purpose. All is quite simple:

connect( ui->lineEdit, SIGNAL(textChanged(QString)), this, SLOT(fillSelector(QString)) );

All worked fine with Qt 5.9.6. But with Qt 5.12.5 I suddenly lost this signal. It is connected as well but does not emit while typing in line. After strike Enter key it emits. And it emits if line is changed programmatically.

In console I see warning message on each typing:

: QMetaObject::invokeMethod: No such method QGraphicsView::inputMethodQuery(Qt::InputMethodQuery,QVariant)

Do not ask me for all code - I cannot give it. And I have no time to make test application. I must find way to fix this bug in my application.

PS: The signal textEdited(QString) does not emit too.

PPS: Just have build same project on Linux desktop for test. It works. In Linux Kubuntu 18.04 QLineEdit emits textChanged() as well. That means - problem is with Android Qt 5.12.5 port. May be there is some issue with QLineEdit settings for Android. It interferes with Android line input used. But I cannot find anything new in docs. In my code changed nothing. I test on same Android device as used before with Qt 5.9.6.

PPPS: Signal textChanged() emits in Android when digital characters are entered. But input validator is not installed for this field:

ui->lineEdit->setValidator( Q_NULLPTR );

And the "input method hints" is set to:

ui->lineEdit->setInputMethodHints( Qt::ImhNone );