Class extends value undefined is not a constructor or null (only on ts-jest)

[amisteriousdeveloper]

I have a legacy project with Create React App. It is working fine.
It builds and run with no problem.

But ts-jest is failing on some files/imports and I can't understand why. It is not that the modules are not being found, but I'm seeing errors like this:

npx jest src/services/realtime-services/realtime-services-factory.spec.ts --no-cache
 FAIL  src/services/realtime-services/realtime-services-factory.spec.ts
  ● Test suite failed to run

    TypeError: Class extends value undefined is not a constructor or null

       8 | } from '../event-keys-factory';
       9 |
    > 10 | export default class InPlayRealTimeBetSlipItemService extends InPlayRealTimeServiceBase {
         |                                                               ^
      11 |   constructor({ brandId, formatter, hub, language, item, onReconnectCallback, releaseUpdateCallback, serviceName }) {
      12 |     super({ brandId, hub, language, item, onReconnectCallback, releaseUpdateCallback, serviceName });
      13 |     this.formatter = formatter;

Since CRA doesn't allow I have a json with this first:

{
  "compilerOptions": {
    "paths": {
      "@/*": ["./src/*"],
      "@public/*": ["./public/*"],
      "@tests/*": ["./__test__/*"]
    }
  }
}

and then in my tsconfig.json I have set

{
   // other configs and...
   "extends": "./tsconfig.paths.json",

For jest.config.js file:

const jestConfig = {
  preset: 'ts-jest/presets/js-with-ts',
  roots: ['<rootDir>'],
  modulePaths: ['.'],
  moduleNameMapper: {
    '^@/(.*)$': '<rootDir>/src/$1',
    '^@public/(.*)$': '<rootDir>/public/$1',
    '^@tests/(.*)$': '<rootDir>/__test__/$1',
    '^axios$': require.resolve('axios'),
  },
  setupFilesAfterEnv: ['./__test__/setup.tsx'],
  transform: {
    '^.+\\.(t|j)sx?$': 'ts-jest',
  },
  testEnvironment: 'jsdom',
};

module.exports = jestConfig;

I've tried everything. But I can't understand why random classes on my project are getting as undefined on for ts-jest. There are some files and modules with

export { default as Something } from './something'

But I'm not sure if this can be the reason.