Why a middleware used in a parent route cannot propagate to sub route?

[tisonkun]

I have a route map like:

const app = new Hono<{ Bindings: Bindings }>({ strict: false });
app.use('*', cors())
app.route('/submit/contact', contact);
export default app;

But the cors middleware doesn't work on '/submit/contact' until I work it around like contact.use('*', cors());.

I'd expect that a middleware used in a parent route should be inherited by sub routes?