The Payment Values Veeva Setting does not have a value on the Profile level. But, the default Organization level Veeva Settings has a value.
The Order_Line_vod.Payment_vod field is displayed as a picklist instead of free text.
The Veeva Setting has values on the Organization level, but null on the Profile level. In this case, the Organization level value defaults to Profile.
This is working as designed.
CRM Help Documentation: Payment Terms