Looking at the logs seems to confirm Alex's suspicions, the app gets a "UbuntuWindow::handleSurfaceFocusChange(false)" event when the login prompt is loaded over the top of it, but never receives "UbuntuWindow::handleSurfaceFocusChange(true)" when the prompt closes.
Looking at the logs seems to confirm Alex's suspicions, the app gets a "UbuntuWindow: :handleSurfaceF ocusChange( false)" event when the login prompt is loaded over the top of it, but never receives "UbuntuWindow: :handleSurfaceF ocusChange( true)" when the prompt closes.