Woocommerce Billing Form not saving User Name or Phone Number?


I have a custom checkout that we’ve built as part of the theme for a site we are building.

When the user presses update to update the shipping or billing address, it wont save the user’s first and last name or their phone number.

I wondered if anyone might be able to help as i am a little stumped here:

<div class="woocommerce-billing-fields">     <?php if ( wc_ship_to_billing_address_only() && WC()->cart->needs_shipping() ) : ?>          <h3><?php esc_html_e( 'Billing &amp; Shipping', 'woocommerce' ); ?></h3>      <?php else : ?>          <h3><?php esc_html_e( 'Billing Address', 'woocommerce' ); ?></h3>      <?php endif; ?>      <?php do_action( 'woocommerce_before_checkout_billing_form', $  checkout ); ?>      <?php $  customer = WC()->customer;?>         <p class="billing-details <?php if(!is_user_logged_in()) {echo 'hide';}?>">             <?php echo             $  customer->get_billing_first_name() . ' ' . $  customer->get_billing_last_name() . ', ';             if(!empty($  customer->get_billing_company())) { echo $  customer->get_billing_company() . ', ';}             echo $  customer->get_billing_address_1() . ', ';             if(!empty($  customer->get_billing_address_2())) { echo $  customer->get_billing_address_2() . ', ';}             echo $  customer->get_billing_city() . ', ' .             $  customer->get_billing_state() . ', ' .             $  customer->get_billing_postcode()             ;?>         </p>         <p class="change-billing-details <?php if(!is_user_logged_in()) {echo 'hide';}?>">Change</p>       <div class="woocommerce-billing-fields__field-wrapper <?php if(!is_user_logged_in()) {echo 'show';}?>">         <?php         $  fields = $  checkout->get_checkout_fields( 'billing' );          foreach ( $  fields as $  key => $  field ) {             woocommerce_form_field( $  key, $  field, $  checkout->get_value( $  key ) );          }         ?>         <p class="update-billing-details updating">Update Billing Details</p>     </div>      <?php do_action( 'woocommerce_after_checkout_billing_form', $  checkout ); ?> </div>  <?php if ( ! is_user_logged_in() && $  checkout->is_registration_enabled() ) : ?>     <div class="woocommerce-account-fields">         <?php if ( ! $  checkout->is_registration_required() ) : ?>              <p class="form-row form-row-wide create-account">                 <label class="woocommerce-form__label woocommerce-form__label-for-checkbox checkbox">                     <input class="woocommerce-form__input woocommerce-form__input-checkbox input-checkbox" id="createaccount" <?php checked( ( true === $  checkout->get_value( 'createaccount' ) || ( true === apply_filters( 'woocommerce_create_account_default_checked', false ) ) ), true ); ?> type="checkbox" name="createaccount" value="1" /> <span><?php esc_html_e( 'Create an account?', 'woocommerce' ); ?></span>                 </label>             </p>          <?php endif; ?>          <?php do_action( 'woocommerce_before_checkout_registration_form', $  checkout ); ?>          <?php if ( $  checkout->get_checkout_fields( 'account' ) ) : ?>              <div class="create-account">                 <?php foreach ( $  checkout->get_checkout_fields( 'account' ) as $  key => $  field ) : ?>                     <?php woocommerce_form_field( $  key, $  field, $  checkout->get_value( $  key ) ); ?>                 <?php endforeach; ?>                 <div class="clear"></div>             </div>          <?php endif; ?>          <?php do_action( 'woocommerce_after_checkout_registration_form', $  checkout ); ?>     </div> <?php endif; ?>