I've tested this with latest 19.10 (updated today) using gnome-session and upstream dash-to-dock installed from gnome-software (can't remember the version now, but I installed it a few minutes ago). The problem is still there when the dock is vertically expanded to fit the screen. I've reported this upstream https://github.com/micheleg/dash-to-dock/issues/1007.
I've tested this with latest 19.10 (updated today) using gnome-session and upstream dash-to-dock installed from gnome-software (can't remember the version now, but I installed it a few minutes ago). The problem is still there when the dock is vertically expanded to fit the screen. I've reported this upstream https:/ /github. com/micheleg/ dash-to- dock/issues/ 1007.