Thanks, I tested it on my machine, still does not work, have no idea why. It works when I delete the jest config from the package.json.
To verify it from an independent machine, I forked your project and added GitHub actions. The tests succeed in the virtual environments, but fail on open db connections.
See my fork here: GitHub - n2o/unit-test-node16
And a sample failing GitHub Action: Copy sample env · n2o/unit-test-node16@7de5467 · GitHub