Crash on QWindowsUiaMainProvider::providerForAccessible

While creating a new QFrame that has checkable QPushButtons and calling setChecked, an accessibility event is being created:

#ifndef QT_NO_ACCESSIBILITY
QAccessible::State s;
s.checked = true;
QAccessibleStateChangeEvent event(this, s);
QAccessible::updateAccessibility(&event);
#endif

This causes a new QWindowsUiaMainProvider to be allocated on the heap. Under some timings, this line: 

auto *provider = qobject_cast<QWindowsUiaMainProvider *>(providerCache->providerForId(id)); 

causes a crash due to a corrupted obj returning from providerCache->providerForId(id)

In our scenario, we are opening multiple (<6) windows that all have a checkable QPushButton and are checked right after creating the window.