Second identical jest test failing after the first one passes

Question

I have two identical jest tests, the first one passes and the second fails. From what I have read it could be something to do with mocking the someFunction. I am clearing all the mocks before each test, I have tried jest.resetAllMocks(); but that does not seem to work.

const authenticatedUser = {
    "id": 1,
    "accessFlags": [],
}

jest.mock("../src/someFunction", () => ({
  return {someData: ["a", "b"]}
}));

describe("My Tests", () => {
  let ex;

  beforeEach(() => {
    jest.clearAllMocks();

    ex = new FauxExpress();
  });

  it("Description", async () => {
    const req = {
      user: { ...authenticatedUser, access: ["admin"] },
    };

    await doSomethingUsingMockedSomeFunction(req, ex.res);

    expect(ex.res.statusCode).toBe(200);
  });

  it("Description", async () => {
    const req = {
      user: { ...authenticatedUser, access: ["admin"] },
    };

    await doSomethingUsingMockedSomeFunction(req, ex.res);

    expect(ex.res.statusCode).toBe(200);
  });
});