I never isolated a way to reproduce this bug, and I haven't encountered it again (even with keeping the extensions enabled). In fact generally the gnome-shell crashes have largely stopped. I'm not sure at what point that was, but for at least the past few days, things that would often crash gnome-shell no longer cause crashes (such as clicking the top-bar widgets on the lock screen, which before reliably triggered https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1868440).
I never isolated a way to reproduce this bug, and I haven't encountered it again (even with keeping the extensions enabled). In fact generally the gnome-shell crashes have largely stopped. I'm not sure at what point that was, but for at least the past few days, things that would often crash gnome-shell no longer cause crashes (such as clicking the top-bar widgets on the lock screen, which before reliably triggered https:/ /bugs.launchpad .net/ubuntu/ +source/ gnome-shell/ +bug/1868440).