We managed to fix it using a different approach.
We re-added the group and fields in the ACF setup, being careful to name the fields the same as what they were named before. The fields then reappeared in the Woocommerce Product records, and the data reappeared in those records that previously had data in the fields.
Not sure what made the field definitions disappear in the first place, but I am suspicious of the latest plugin upgrade.
I have the same problem. I am using ACF to add a couple of custom fields to our Woocommerce product records. As of last week, we can no longer see the custom fields. They are still in the database, but are not accessible to edit.
Any help on how to restore their view would be greatly appreciated, as this is causing a real problem with website maintenance.
