Jackson type info is lost in a GET request returning a collection of objects

I'm having a simple class hierarchy: an abstract class AbstractCustomer and 2 derived concrete classes.
1) When the GET request's method directly returns a list of objects of AbstractCustomer, then the mapping information is available (as defined with @JsonTypeInfo and @JsonSubTypes)
2) However, when the GET request's method returns a Response object encapsulating the same list (plus a link header), then the mapping information isn't sent to the client.
I'll attach a testcase.