Hi Paul,

When you switch to the new WooCommerce HPOS table, all orders are stored in a different table in the database and not anymore in the post table. This also means that the custom fields for the ‘old’ post-type order do not work anymore in ACF. All metadata for HPOS order are also stored in a different table order_meta instead of the post meta table.

As far as I know, ACF does not switch the custom fields for Orders as well. When I open an order in HPOS mode, I don’t see the ACF fields that I defined for the ‘Order’ Post type, and that is what I suspect. Our plugin does have support for the HPOS order table, and we even have an Order Meta column that allows you to show the Order metadata instead of the Custom fields on the order table.

However, our plugin does not have support for ACF fields that are defined for HPOS orders. This is because ACF does not support this at this moment.