I have a Zoho Sign application form that I pre-fill via Zoho Flow, following a telephone call. The signer can change the information in the pre-filled fields, if there are errors.

The sign template has a number of fields - some text and some dropdown.  The text fields show perfectly within Zoho Flow. but the dropdown fields don’t show at all. 

Have I done something wrong, or is this just an issue with how they integrate?