Purpose

To explain regarding the different behavior by the fields in JIRA:

Navigable: Possible to see the field in the issue navigator 
Orderable: Possible to place it on "screens".

• Field with no 'Orderable' value, will not be able to be visible in the 'Screens' in JIRA

In order to identify which fields has what value for this two property, run the following in your browser's URL:

http://<YOUR JIRA URL>/rest/api/2/field

This will return an API result for all the fields available in your instance, together with the orderable and navigable value. To find the field that is not orderable, simply find for "orderable":false.