Is the download from zotero.org not the official version?
sudo apt uninstall zotero
curl -L https://raw.githubusercontent.com/retorquere/zotero-deb/master/uninstall.sh| sudo bash
curl -L https://raw.githubusercontent.com/retorquere/zotero-deb/master/install.sh | sudo bash
I don't recall doing a git, but it's possible that I did a sudo apt install zotero.
curl -L https://...../install.sh | sudo bash
sudo apt install zotero
If I'm grokking what you say