Hi Justin! Original reporter here -- I've been running Ubuntu 18.10 since release, and I've never once been able to reproduce this issue on that version.
I have the same gnome-shell version as you, and I tested Firefox 65 (official version from Ubuntu repos) and am still unable to reproduce.
I'd suggest you file a new bug and link it from here.
Hi Justin! Original reporter here -- I've been running Ubuntu 18.10 since release, and I've never once been able to reproduce this issue on that version.
I have the same gnome-shell version as you, and I tested Firefox 65 (official version from Ubuntu repos) and am still unable to reproduce.
I'd suggest you file a new bug and link it from here.