There is an issue where you cannot specify a specific location for a windowed packaged game when using a command line to open the project, the project will move to that position for a brief moment before moving to the center of the screen. This issue appears to be a regression
4.15.3 - CL: 3450819 - Issue does not occur
4.16.3 - CL: 3561208 - Issue occurs
4.17.2 - CL: 3658906 - Issue occurs
4.18.1 - CL: 3754814 - Issue occurs
4.19.0 - CL: 3776583 - Issue occurs
Result: The project will open in the correct size and location then the window will move to the center of the screen
Expected result: The window open with the correct size and in the correct location.
Head over to the existingAnswerHub thread and let us know what's up.