Jackson deserialization of interface affects constituent member's deserializaton

Question

I have an interface type with many implementation classes. I can serialize/deserialize this either by

@JsonDeserialize(using = AlarmStateDeserializer.class)
@JsonSerialize(using = AlarmStateSerializer.class)
@JsonTypeInfo( use = JsonTypeInfo.Id.NONE)
public interface AlarmState
{
  :

or

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.EXISTING_PROPERTY, property = "type")
@JsonSubTypes({
    @JsonSubTypes.Type(value = AcknowledgedState.class, name = "acknowledged"),
    @JsonSubTypes.Type(value = ActivatedState.class, name = "activated"),
    @JsonSubTypes.Type(value = DeactivatedState.class, name = "deactivated"),
    @JsonSubTypes.Type(value = BlockedState.class, name = "blocked"),
    @JsonSubTypes.Type(value = ReactivatedState.class, name = "reactivated"),
    @JsonSubTypes.Type(value = DisabledState.class, name = "disabled"),
    @JsonSubTypes.Type(value = NormalState.class, name = "normal"),
})

and that works fine when I seralize/deserialize the AlarmState directly in the ObjectMapper.

BUT, if I include the AlarmState as a property in another type, it insists to have a type for that field.

I have tried just about every other way I can think of, but for instance;

@JsonTypeInfo( use = JsonTypeInfo.Id.NONE )
@JsonDeserialize(as = AlarmImpl.class)
public interface Alarm
{
    AlarmState getState();
  :

(It doesn't matter if I deserialize the AlarmImpl directly either, same result)

And I will get the following exception;

Could not resolve subtype of [simple type, class com.sensetif.pipes.alarms.AlarmState]: missing type id property 'type' (for POJO property 'state')

I have also tried to put all kinds of annotations on the getState() method, but to no prevail.

FTR; the json in question is;

{
  "labels": [],
  "state": {
    "name": "normal",
    "description": "Normal state indicates everything is fine.",
    "creationTime": "1970-01-01T00:00:00Z"
  },
  "counter": 0,
  "name": "niclas1",
  "description": null,
  "condition": false,
  "alarmClass": "C",
  "organization": 0,
  "parameters": null
}

How can it be that the underlying type deserializes fine, but not when it is part of an outer object??