Customer reports when they are submitting a form in Service Catalog, fields are not being populated with the provided information.
This has always been an issue and has never worked correctly before.
Release : 17.3
Component : SDM - Catalog
The script for the offering was not written correctly.
Correcting the code written in the script allowed the fields to be populated correctly.
Try importing a copy of the offering into your lab environment to see if the issue persists.
If the issue persists in the lab environment have the customer reexamine their code.