Refactored all logic into hooks but now stuck using a conditional

Question

I've refactored all the business logic by hiding it behind hooks.

Before:

function App({productId}) {
  const [item, setItem] = useState(null);
  const [isLoading, setIsLoading] = useState(false);
  useEffect(() => {
    setLoading(true);
    (async () => {
      const found = await useContext(Store).find(productId);
      setItem(found);
      setIsLoading(false);
    })();
  }, [item, products]);
}

After:

function App({productId}) {
  const [item, isLoading] = useProductId(productId);
}

But how suddenly someone brought up a problem when productId is null. I know I can't do:

function App({productId}) {
  if(!productId) {
    return (<Loading />);
  }
  const [item, isLoading] = useProductId(productId);
}

Is my only recourse to go back and change all the hooks to accept null? Because technically null isn't an error state nor is it a loading state.