Every time I open a dialog, it is shown in a sligtly different position than the one where it was when it was previously closed.

The problem seems to happen when the Dialog has a layout and it is resized when it is created.

Attached is a small example demonstrating the issue. Click on "Open Dialog" to open a dialog. Close it. Click the button again. The new dialog position is not the previous position. Do it multiple times, the dialog will move every time it is opened.
Click "Open Dialog Loop" to automatically open and close the dialog multiple times, you should clearly see the dialog moving (see attached animation).

I can reproduce this issue on Windows.