Thanks for your reply. You’re probably right, but I’m struggling with versions of Python libraries: the ‘EXTERNALLY-MANAGED’ feature of pip (see e.g. https://bbs.archlinux.org/viewtopic.php?id=286788) means that I have to install everything that AxiDraw needs in a new Python virtual environment using pipx, and that insists on giving me the latest version of lxml (5.1), so I’m still seeing the error.
I’ll report back once I’ve got my head round this Python library versioning mystery.