--skip-existing tag does not work when pushing to Gitlab Package Registry

skip-existing tag does not work when pushing a Python package to Gitlab Package Repository

I work on an open-source project in Python, which aims to push a package on the Gitlab Package Repository. But unlike local install of twine, the one used by our CI/CD job fails when required to push an existing version of the package, despite the --skip-existing tag. See an example here.

Note: As my project is open-source, I guess runners are triggered with Gitlab EE.