A dialog which is created by MessageDlg function can not be moved relative to the parent window. It looks like the dialog is glued to the form which created it.
If we drag the dialog, the caller form also moved along the dialog.
To demonstrate the problem, show a MessageDlg from a form and then try to move the dialog. I have attached a simple project to demonstrate this.
fpc version: 3.2.0
lazarus version : 2.10.0
o/s: linux ubuntu 18.04
Is it a bug or a feature?