Steps to Reproduce:
- Create a custom field for order item.
- Create a new order by adding at least one item to the cart and checking out.
- At "Control Panel > Commerce > Orders" select your order by clicking on the orderId.
- Select an item from the order by clicking on the SKU.
- Select the "Custom Fields" tab.
- An input for the custom field you created should be displayed.
- Update the value for the custom field and click save.
The new value should persist.
A toast success message is displayed but the field is not persisted.
See Attached Gif.
The same issue may exist in other commerce custom field implementations. It may be helpful to review all other occurrences as shown in the attached image: CommerceCustomFields.png.