OrderBy spring-cloud-gcp-starter-data-firestore is not working for inside field (i.e. person.Name)

I have a document Resource { id, person: { Name}} and I'm trying to query the collection sorting by person.name but I'm receiving the following error:

"message": "Persistent property does not exist: person.Name",
"requestId": "5a9ea081-1",
"trace": "java.lang.IllegalArgumentException: Persistent property does not exist: person.Name\n\tat com.google.cloud.spring.data.firestore.repository.query.PartTreeFirestoreQuery.createFirestoreSortOrders(PartTreeFirestoreQuery.java:190)\n\tSuppressed: The stacktrace has been enhanced by Reactor, refer to additional information below: \nError has been observed at the ...."

The attribute exists and is never null, also, I've created index for that.