Property name $id leads to TypeError unhashable type 'dict', expected behaviour?

[GeraldIr]

I read here https://swagger.io/docs/specification/data-models/keywords/ that $id is not supported as a json keyword, so is that error expected behavior?

I've raised the issue about having this name in a specific openAPI specification as it makes me unable to work with openapi-core library unless i locally rename these property names to something like "$idn". I've been told that this is a tooling issue on openapi-core libraries end and that using "$id" is perfectly valid according to the documentation.

I didn't want to raise this as a bug as it is unclear to me who is correct here. Is this actually a bug or intended behavior?