[solved] cannot render `isSubmitting` changes

const form = useForm(
  onSubmit: async ({ value }) => {
    console.log('before onSubmit')
    await fetch('/post', {
      method: POST,
      body: JSON.stringify(value)
    })
    console.log('after onSubmit')
  }
)

<form.Subscribe selector={({ isSubmitting }) => isSubmitting}>
  {(isSubmitting) => <button disabled={isSubmitting}>submit</button>
</form.Subscribe>

submitButton clicked
submitButton selector {isFieldsValid: true, isSubmitting: false}
submitButton selector {isFieldsValid: true, isSubmitting: true}
before onSubmit
after onSubmit
submitButton selector {isFieldsValid: true, isSubmitting: false}
submitButton render {isFieldsValid: true, isSubmitting: false}