Type of mediatype is not unique in response body if changing the default media type

GIVEN a user with a default mediatype application/json inside the general settings of API Designer

WHEN adding a body in the response of an operation with an additional mediatype application/xml and saving it.

WHEN changing the default mediatype to application/xml in the general settings instead of application/json 

THEN both application/xml mediatypes appear in the operation whilst the mediatype of the response body should be unique (see gif)