Regardless, if you don't have the phone field you should populate it with the number from the address field (since it's the same number)

Not what I see, it's populated!

please look below to the difference between a phone field and the address field, as you can see the phone field is empty thus the reason for being empty in frontflip

The phone field. Why would I look in the address field for a phone number?

See attached a recent order as an example, no phone recorded in FrontFlip

are you looking in the address field or the phone field? it is updated from the phone field of the customer

Menan Sub it's not populated though....

customer phone is populated from customer phone field in shopify, or phone added in Shopify POS.