An attribute is visible/editable if:
1 - No "Access to attributes" is assigned to the user, and the attribute is defined as "visible".
To check if "Access to attributes" is assigned, go to Admin -> Users -> Edit -> Access to attributes.
To check if the attribute is defined as visible, go to Admin -> Attributes, then select the attribute.
2 - "Access to attributes" is assigned to the user, and this access declares the attribute as visible.
Once you have checked the Access to attributes (as indicated above), examine the details of this profile in Admin -> Access to attributes.
Select the relevant profile by clicking on the Edit icon.
Finally, make sure that the Show icon is activated (see below):
For further information, please refer to the documentation.
Keywords: Access to attributes, Users, Administrator (Admin), Attributes, Profile.