Comment 34 for bug 2034664

Alan, the fix for mantic is released in version 87ubuntu2, not 87ubuntu1. It was published to mantic updates last November so I'm not sure why you wouldn't have received it yet.

You can grab it directly from:
https://launchpad.net/ubuntu/+archive/primary/+files/gnome-shell-extension-ubuntu-dock_87ubuntu2_all.deb