AlertWindow and modal/alwaysontop

I’ve got a window, centred which is set to always on top and is in entermodalstate.

I have an alertwindow sometimes popping up behind it which then seems to also enter a modal state. The user can’t see the alert window to dismiss it, because my other always on top window is in front. I’m calling AlertWindow::showMessageBoxAsync().

I’m scratching my head about this one… anyone else had this? Solutions?