Invalid state: ReadableStream is already closed error causing from rederect() in next js 14

I am using next 14. using server action. this is the function:

export async function login(prevState: any, formData: FormData) {
  const result = loginSchema.safeParse(Object.fromEntries(formData));

  if (!result.success) {
    return {
      errors: result.error.flatten().fieldErrors,
    };
  }

  const { username, password } = result.data;

  if (username !== testUser.username || password !== testUser.password) {
    return {
      errors: {
        username: ["Invalid username or password."],
      },
    };
  }
  await createSession(testUser.id);

  redirect("/dashboard");
}

The function works perfectly in terms of validating the form, but when it comes to redirecting, it simply does not.
Trying to debug this for a day, but no clue what’s the problem,

this is the error from the server console:

⨯ Internal error: TypeError [ERR_INVALID_STATE]: Invalid state: ReadableStream is already closed

at ReadableByteStreamController.enqueue (node:internal/webstreams/readablestream:1175:13)