Contact person info from Customer Invoice on print form

Hi experts,

I am having trouble with retrieving contact person name from Customer Invoice on print form.

In Adobe LC designer, I use the following binding path.

$.CustomerInvoice.BillToParty.ContactPerson.FormattedName

For some accounts and transaction, the binding path works.

For some accounts, it doesn't work.

I cannot figure out what is the difference.

Any ideas?

Thanks and Best Regards

Fred