QActionGroup exclusiveness is broken in some situations

auto group = new QActionGroup(this);
auto action1 = group->addAction("1");
auto action2 = group->addAction("2");
auto action3 = group->addAction("3");

action1->setCheckable(true);
action2->setCheckable(true);
action3->setCheckable(true);

// action2 will be checked in lambda directly connected to action1::toggled signal
connect(action1, &QAction::toggled, this, [action2](bool active) {
    if (!active)
        action2->setChecked(true);
});

action1->setChecked(true);
assert( action1->isChecked());
assert(!action2->isChecked());
assert(!action3->isChecked());

// activate lambda described above
action3->setChecked(true);
assert(!action1->isChecked()); // true.  action1 is not checked
assert(!action2->isChecked()); // FALSE. action2 is checked
assert( action3->isChecked()); // true.  action3 is checked