Frequently Asked Question
Modal windows do not move, instead the entire Viewer window moves, then returns to the center. (Ubuntu 18 Gnome)
Last Updated 3 years ago
The problem occurs in the Gnome desktop environment in Ubuntu 18
Solution Link
The following commands may also work:
$ sudo apt install gnome-tweaks
Run
$ gnome-tweaks
In the windows section set Attached modal dialogs to off