When a form is exported, some of the fields are missing completely.
There is a "begin_split" on the form that is not closed. All the fields after this "begin_split" will be missing on the PDF Export.
End the split by adding a "end-split" or replace the "begin-split" with an "end-split"
The solution will be based on how the form is being configured. Nonetheless an open split cannot be left on the form, the split needs to be closed on the form for the PDF export to work as expected.