User custom field not display in the backend edit profile
From Joomla! Documentation
Errors reported
User custom field is not displayed and can't be edited in the backend user edit account. Works fine in frontend edit profile.
Versions affected
General Information
This pertains only to Joomla! version(s): 3.7.0
What is the cause
Currently the fields that are displayed there are hardcoded.
Known Problem
This is a known problem that is awaiting a fix in a future release: https://github.com/joomla/joomla-cms/issues/13601