Why is the Patient.gender in the expanded ValueSet not working

[linforestzhang]

Why is the Patient.gender in the expanded ValueSet not working?

using FHIR version '4.0.1'

include FHIRHelpers version '4.0.1'
include FHIRCommon version '4.0.1'

// It's an expanded ValueSet:
valueset "Administrative Gender": 'http://hl7.org/fhir/ValueSet/administrative-gender'

// Working:
define "CodeInValueset":
	Code { system: 'http://hl7.org/fhir/administrative-gender', code: Patient.gender } in "Administrative Gender" 

//Not Working:
define "GenderInValueset":
	Patient.gender in "Administrative Gender"

However, for the Patient.maritalStatus of type CodeableConcept, the latter syntax works:

// Expanded ValueSet
valueset "Marital Status": 'http://hl7.org/fhir/ValueSet/marital-status'

Patient.maritalStatus in "Marital Status"

My Local Environment:
openjdk 17.0.7 2023-04-18
VSCodium 1.91.1
Clinical Quality Language (CQL) for VSCode v0.1.1