running application after windeployqt produces weird glitches

Tried to deploy a qtquick.2 application using windeployqt, and the outcome was a program that ran, but behaved strangely. For example, had unclickable surfaces, components with wrong size or wrong color.

I initially thought of a buffer overrun or something similar, but there is no such problem - it seems the problems were all fixed when I created a "qml" directory where the binary was, and moved the deployed Qt, QtGraphicalEffects, QtQml, QtQuick and QtQuick.2  directories in it.

It might not be necessary that all of them are moved inside the qml directory - I do not really understand the nature of the problem.

The application would otherwise run fine in the "build environment", or when qtcore.dll is not patched.

The deployment tool was invoked as follows:

path_to/windeployqt --release --qmldir my_project_qmldir   path_to/pe_name

A short case to reproduce is not so easy to write, as the glitches appear somewhat inconsistently.