(Allegedly) wrong behaviour of GNOME Shell for modal dialogues on Wayland only
In https://github.com/syncthing/syncthing-gtk/issues/424#issuecomment-383281224 a developer complains about GNOME Shell focussing a newly created modal dialogue. In that case, it is particularly annoying, because the dialogue has a button which is focussed and which is triggered when pressing the space bar or the enter key. When activating that button, the application quits. It's very easy to type some text, like here on this Web page, and hit the space bar while that dialogue opens.
Supposedly, that behaviour only happens on Wayland.