ts-node isn't an official part of the TypeScript project. It has notoriously bad module support.

Try this:

    // tsconfig.json
    {
      "compilerOptions": {
        "outDir": "dist",
        "module": "es2020",
        "allowJs": true
      },
      "files": ["index.ts"]
    }

    // index.ts
    import('./test.mjs').then(console.log)

    > npx tsc && node ./dist/index.js
    [Module: null prototype] { Foo: [Function: Foo] }