"Included" related resources are wiped if server does not support compound documents

[jhash]

From: https://jsonapi.org/format/#document-compound-documents

To reduce the number of HTTP requests, servers MAY allow responses that include related resources along with the requested primary resources. Such responses are called “compound documents”.

Our server is one that doesn't (yet) support compound documents and the nested arrays of related resources are returning empty even though under relationships there are a few of them. I would expect that the objects are still included in the serialized final parent object but they just have the bare minimum of id defined. What do you think?

Thanks!