I am creating a new doctype and some fields that i have input in the DocType are not showing when trying to test that new doctype. The ‘hide’ visibility option is not checked either so i am not sure what the problem is. In these fields, only Serial No, Sales Order, Item Code and Supplier are showing.
One thing to check is whether any of the fields not appearing are read-only and empty; those tend not to appear at all (I assume this is part of Frappe design).
Ready-only can be set by the data type (like your Customer field) and fields whose read-only flag is set to Yes on the doctype, or set via conditions. Also fields that whose values are always fetched also behave like read only.