Super + search not working after upgrade to 19.10
I experienced the same issue after updating to Ubuntu 19.10.
The following was able to solve it for me:
sudo apt-get --reinstall install yaru-theme-gnome-shell
Followed by a reboot.
I also disabled shell extensions prior to that but I'm not sure if that was necessary
I had at some point installed the yaru colors theme and my thought is that didn't play well with the update, removing the theme alone wasn't enough and I had to re-install the default yaru theme provided with Ubuntu.