I just tried my application with a build of the current 5.12 branch (yesterday), and I see that a QSplashscreen is now positioned at the top left corner on an Android instead of the center of the Window. This is a regression from Qt 5.12.1!
Looking through the changes since Qt 5.12.1, this seems to be a regression coming from https://codereview.qt-project.org/#/c/249238/ .
See the attached project for a minimum example.
See a splash screen with Qt image in the center of the screen on an android device.
Behaviour in my Qt build ( ef7908d90cd4acfd3dc9ddeb5dca4e9d53dde9d8 ):
Splash screen with Qt image is on the top left corner of the screen on an android device.