$ref to external component are not add as shared component for open API 3.1 but recreated for each usage

As describe in this issue https://github.com/OpenAPITools/openapi-generator/issues/18361 I have a difference in the parser behavior.

With 3.0 schema, the reference to an external component is parse with it's own structure. It allow to have a common implementation for things like mapping (an exemple with a comme Amount component that reproduce the issue is available here: https://github.com/pkernevez/pb-openapi).

With 3.1 schema the parsing don't create common components, there are new classes (with the attributes) for each usage.
It's not possible to have shared Dto anymore nor share mapping implementation.

It try with and without setResolveFully (as I saw https://github.com/swagger-api/swagger-parser/issues/1950 that seems to be closed to this issue, but isn't).
Output without setResolveFully

Output with setResolveFully

Start with the reproducer linked in the issue at github.com/pkernevez/pb-openapi and compare parsing of the external component under OpenAPI 3.0 and 3.1, both with and without setResolveFully. Trace how external $ref components are represented for repeated usages. Done means OpenAPI 3.1 preserves a shared component structure instead of creating new classes for each usage.