Problem rendering using OpenGL in VM

[xtal256]

Ok, i have been playing around this, seeing how things render using the Qt paintEvent() function as opposed to the paintGL() one. I am seeing even more inconsistencies than before.
Since i also want to render text on the OpenGL surface, i tried the following code:

void MapView::paintEvent(QPaintEvent*) {
    QPainter painter(this);
 
    painter.setBackground(Qt::black);
    painter.setPen(Qt::red);
    painter.drawLine(0, 0, 300, 300);
    painter.drawPixmap(10, 10, testImage);
 
    QFont font("Arial", 40);
 
    font.setStyleStrategy(QFont::ForceOutline);
    painter.setRenderHint(QPainter::Antialiasing);
    QPainterPath textPath;
 
    textPath.addText(20, QFontMetrics(font).height()+150, font, "Hello, World");
    painter.setPen(QPen(Qt::cyan, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
    QLinearGradient gradient(0, 0, 0, 100);
    gradient.setColorAt(0.0, QColor(255, 0, 0));
    gradient.setColorAt(1.0, QColor(0, 0, 255));
    painter.setBrush(gradient);
    painter.drawPath(textPath);
 
    painter.setPen(Qt::yellow);
    painter.drawText(150, 100, "Hello again");
}

void MapView::paintEvent(QPaintEvent*) {
    QPainter painter(this);

    painter.setBackground(Qt::black);
    painter.setPen(Qt::red);
    painter.drawLine(0, 0, 300, 300);
    painter.drawPixmap(10, 10, testImage);

    QFont font("Arial", 40);

    font.setStyleStrategy(QFont::ForceOutline);
    painter.setRenderHint(QPainter::Antialiasing);
    QPainterPath textPath;

    textPath.addText(20, QFontMetrics(font).height()+150, font, "Hello, World");
    painter.setPen(QPen(Qt::cyan, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
    QLinearGradient gradient(0, 0, 0, 100);
    gradient.setColorAt(0.0, QColor(255, 0, 0));
    gradient.setColorAt(1.0, QColor(0, 0, 255));
    painter.setBrush(gradient);
    painter.drawPath(textPath);

    painter.setPen(Qt::yellow);
    painter.drawText(150, 100, "Hello again");
}

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On the VM, the gradient is not rendered (it's just a white rectangle), but the blue outline is. But, on my physical machine, it still does not render the gradient correctly. And the plain yellow text is not yellow and looks a bit squashed up.
I also tried turning on 3D acceleration in the VM and got different results still.

Here are some screenshots to explain better:
test.png

This is quite disappointing as i had hoped to use Qt's code for rendering text and images. It looks like i will just have to use 3rd party libraries or my own code, as i have been doing in the past. Sure would have been easier doing it all using Qt.