Custom item field not showing up as expected

We have created a custom item field that collects a string of text (phone number) for one specific item.

The field shows up on the item and displays in the checkout. However, after that, it does not show up anywhere. Not in any emails or in the backend administrator when viewing the order or on the invoice, etc.

The only display override we are using is for the invoice. I've deleted the override and it still does not appear.

Custom field settings are attached.

Please advise.

Joomla v3.7.4
Hikashop v3.1.1

I've tried a few of the suggestions mentioned in the forum. Specifically:
www.hikashop.com/forum/install-update/88...-invoice.html#273758
www.hikashop.com/forum/checkout/891359-c...n-emails.html#275187
www.hikashop.com/forum/checkout/891280-c...n-emails.html#275134

The info in these did not help resolve the issue.

To recap, we are having 3 issues:
1) Custom item field is not showing up in emails
2) Custom item field is not showing up when viewing the order
3) Custom item field is not showing up on the invoice

We are not using any custom views for emails.
We are using a custom view for invoice. However, deleting the custom view results in the same issue.

It is worth noting that custom order fields are showing up as expected. It is just custom item fields that are not working.

Display settings are all enabled (as demonstrated in the attachment).

HikaShop Business 3.1.1 [1706012215]

Attached is a screengrab of the related product.

Please let me know if anything else is needed.

That did it. Thank you!