QPushButton; "Blurry" stylesheet for checked buttons

[Smeeth]

I have two buttons in a button group, and I want the checked button to have a blue background with white text, and the unchecked button white background with blue text.

This my GUI setup:

    mvLBtn = new QPushButton("btn1");
    mvLBtn->setCheckable(true);
    mvLBtn->setChecked(true);
    mvMlBtn = new QPushButton("btn2");
    mvMlBtn->setCheckable(true);

    QWidget *mvGrp = new QWidget;
    QButtonGroup *mvBGp = new QButtonGroup;
    mvBGp->addButton(mvLBtn);
    mvBGp->addButton(mvMlBtn);
    QHBoxLayout *mvLayout = new QHBoxLayout;
    mvLayout->setMargin(0);
    mvLayout->setSpacing(0);
    mvLayout->addWidget(mvLBtn);
    mvLayout->addWidget(mvMlBtn);
    mvGrp->setLayout(mvLayout);

This mvGrp widget is added the form later in a couple nested layouts.

This is my stylesheet:

this->setStyleSheet("QPushButton{margin: 0px; padding: 10px;}"
                        "QPushButton:checked{background-color: blue; color: white;}"
                        "QPushButton:!checked{background-color: white; color: blue;}");

For some reason, the checked button (btn1) is blurry on the form.

However, I've noticed that if I switch my stylesheet for checked vs !checked, the unchecked button does NOT have the same blurry affect.

Switched stylesheet:

this->setStyleSheet("QPushButton{margin: 0px; padding: 10px;}"
                       "QPushButton:checked{background-color: white; color: blue;}"
                       "QPushButton:!checked{background-color: blue; color: white;}");

Form with btn1 checked:

How can I get my form to have a solid blue background on checked buttons?