lat9:
Well, :censored:, I missed that one. You can edit /includes/modules/pages/checkout_one/jquery.checkout_one.js, finding
function changeShippingFields(event)
{
jQuery(this).addClass('opc-changed');
jQuery('#checkoutOneShipto .opc-buttons, #opc-ship-save').show();
jQuery('#checkoutPayment > .opc-overlay').addClass('active');
jQuery('#checkoutOneShipto').removeClass('visibleField');
jQuery('#checkoutOneShipto').addClass('opc-view');
}
> and changing to
> ```
function changeShippingFields(event)
{
jQuery(this).addClass('opc-changed');
jQuery('#checkoutOneShipto .opc-buttons, #opc-ship-save[B], #opc-add-ship, #opc-add-ship+label[/B]').show();
jQuery('#checkoutPayment > .opc-overlay').addClass('active');
jQuery('#checkoutOneShipto').removeClass('visibleField');
jQuery('#checkoutOneShipto').addClass('opc-view');
}
If your site is using minified scripts, you'll need to push that unminified version through a minifier; I use https://jscompress.com/.
Still no luck.
I tried OPC 2.3.2 on a fresh install of ZC 1.5.6 with no add on but the same thing happens.
Shipping address is not being registered in the address book.

I am not an expert but I added the following code in /templates/templates_default/tpl_checkout_shipping_address_default.php
<?php
if ($show_add_address) {
?>
<?php echo zen_draw_checkbox_field("add_address['ship']", 'style="display:inline"','1', false, 'id="opc-add-ship"' . $parameters); ?>
<label class="checkboxLabel custom-control-label" for="add_address['ship']" title="<?php echo TITLE_ADD_TO_ADDRESS_BOOK; ?>"><?php echo TEXT_ADD_TO_ADDRESS_BOOK; ?></label>
<?php
The check box and text is displayed but it did not fix my problem of the address not being registered in the address book. OPC is really great but this issue has me clueless.

I also apologize for pushing on my issue and appreciate everyone trying to help.
Thank you again