Third argument is optional, default value is true, but yes.
If get_queried_object() is returning a term and the term returned has a value for the field “about_schema” then there is no reason it should not be working.
Is your field nested in a repeater, or group field?
Double check your field name. Double check that the field has a value.
Check to make sure your field name is not colliding with something else, another input field either in ACF or another plugin that might be adding fields to terms.
