Test suite fails with clean repo

[CoranH]

I can't get the test suite to run cleanly locally. I simply git clone the repo, run "yarn && yarn build && yarn test", and almost every test fails with:
SyntaxError: Cannot use import statement outside a module
I can't find any info on how my system might need to be setup to run the test suite. Running Ubuntu 22.04.1, Node v16.18.1.
The little I can garner from Google suggests this is related to Jest not being able to read ES Modules.