Expanded codes of Value set with filter "op" : "is-not-a" includes the code that should not be included

[aswathikrishnan24]

Describe the bug

Value set http://hl7.org/fhir/ValueSet/patient-contactrelationship(326) expanded by car tool for us core package has a filter "op" : "is-not-a". But O is included in the expanded value sets.

 "compose" : {
    "include" : [{
      "system" : "http://terminology.hl7.org/CodeSystem/v2-0131",
      "filter" : [{
        "property" : "concept",
        "op" : "is-not-a",
        "value" : "O"
      }]
    }]
  }

Expanded value set
BP
C
CP
E
EP
F
I
N
O
PR
S
U

To Reproduce
Steps to reproduce the behavior:

1. Verify the Code system and the filter in Value set : https://hl7.org/fhir/R4/valueset-patient-contactrelationship.json.html
2. Verify the Codes from Code system : https://terminology.hl7.org/5.5.0/CodeSystem-v2-0131.json.html
3. Use latest car file of Us-core-test-5.0.1 generated by car tool 2.1.2
4. Go to Codes Table and navigate to Value set Id 326
5. Verify the Codes

Expected behavior
Code O should be omitted and not displayed in Codes Table.

Version used:
FHIR Version: [R4]
Car tool Version: [2.1.2]
Us-core-test-5.0.1 package