QAndroidPlatformScreen sometimes left without nativeSurface after return from background

After return from background (and sometimes just after launch), QAndroidPlatformScreen::setAvailableGeometry() is called without subsequent surfaceChanged(). As a result, application is visible, can respond (internally) to taps, buttons etc, but main screen in never redrawn.

I strongly feel that it is related to bottom button bar sometimes auto-hiding and sometimes not.