How to update helper text of two interdependent inputs?

Question

Let's say I have a date range and I want to validate that the start date is smaller than the end date and vice versa.

const schema = yup.object().shape({
  startDate: yup
    .date()
    .when('endDate', (endDate: Date, schema) => schema.max(endDate)),
  endDate: yup
    .date()
    .when('startDate', (startDate: Date, schema) => schema.min(startDate)),
}, 
[['startDate', 'endDate']]);

Now I'm using react-hook-form with an inputs of type date

const { control } = useForm({
  mode: 'onBlur',
  resolver: yupResolver(schema),
});

<MaterialTextField
  inputRef={ref}
  error={isTouched && invalid}
  onBlur={onBlur}
  helperText={error?.message}
  type="date"
/>

With this example, it's working fine, but when a helper text is displayed, if one of the fields is changed and the values become valid, I would like both fields helper text to be removed, except the only one disappearing is the touched one.