Form not updating when connected value is updated (Redux Form)

I am building a form using React and Redux Form. I use the formValueSelector to connect to several input fields. However, when I update these input fields in the UI, the form is not re-rendered. My code looks like this:

// HelpForm.jsx

import React from 'react';
import { connect } from 'react-redux';
import { reduxForm, formValueSelector } from 'redux-form';

import CategorySelectBlock from 'apps/help_form/components/CategorySelectBlock';

const selector = formValueSelector('help_form');

const mapStateToProps = state => ({
    category: selector(state, 'category'),
    subcategory: selector(state, 'subcategory')
});

class HelpForm extends React.Component {
    render() {
        const {
            category,
            subcategory
        } = this.props;

        console.log('Rendering HelpForm');
        console.log('category:', category);
        console.log('subcategory:', subcategory);

        return (
            <form id="helpform">
                <CategorySelectBlock
                    category={category}
                    subcategory={subcategory}
                />
            </form>
        );
    }
}

const ReduxHelpForm = reduxForm({
    form: 'help_form'
})(HelpForm);

export default connect(
    mapStateToProps
)(ReduxHelpForm);

I can see from my console logs that this HelpForm component is only rendering once, even after I select a new value for the category or subcategory fields (these are defined within the CategorySelectBlock component).

Am I doing something wrong, or misunderstanding how formValueSelector works? Any guidance would be much appreciated. Thank you!