ERROR HAPI-2071: Invalid filter criteria - code does not exist

[ghaliouss]

NOTE: Before filing a ticket, please see the following URL:
https://github.com/hapifhir/hapi-fhir/wiki/Getting-Help

Describe the bug

We had an error when calling this valueset by url with expand : https://hapi.fhir.org/baseR4/ValueSet/$expand?url=https://xxxx.fr/ig/fhir/yyy/ValueSet/xxxx-yyy-zzz-mat-allaitement-vs

The error message is saying that the code system does not exist which is not true, here is the get call of the codesystem:
https://hapi.fhir.org/baseR4/CodeSystem?url=https://xxxx.fr/ig/fhir/yyy/CodeSystem/xxxx-yyy-maternite-cs

To Reproduce
Steps to reproduce the behavior:

1. Get call the valueset by url: https://hapi.fhir.org/baseR4/ValueSet/$expand?url=https://xxxx.fr/ig/fhir/yyy/ValueSet/xxxx-yyy-zzz-mat-allaitement-vs

Expected behavior

Getting 200 as response code and this payload as response payload valueset xxxx-yyy-zzz-mat-allaitement-vs.json

Screenshots

Environment (please complete the following information):

• HAPI FHIR public server: https://hapi.fhir.org/baseR4