This might not be a problem related to angular, but to fact that the verv DELETE might no have a body attached. It is used to delete resources, so its response should only be the code.
Now I do recommend to test your end point with POSTMAN, so you can double check that you are receiving the body. Then if you are sure that the body is there after using postman, then we might be able to do something about this body.
You can also check your chrome console on the network tab to check the response on the DELETE request.
I did run on this problem a few years ago.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/DELETE
Request has body  May
  Successful response has body  May
  Safe  No
  Idempotent    Yes
  Cacheable No
  Allowed in HTML forms No 
https://restfulapi.net/http-methods/#delete
HTTP DELETE
  As the name applies, DELETE APIs are used to delete resources (identified by the Request-URI).
A successful response of DELETE requests SHOULD be HTTP response code 200 (OK) if the > response includes an entity describing the status, 202 (Accepted) if the action has been queued, or 204 (No Content) if the action has been performed but the response does not include an entity.
DELETE operations are idempotent. If you DELETE a resource, it’s removed from the collection of resource. Repeatedly calling DELETE API on that resource will not change the outcome – however calling DELETE on a resource a second time will return a 404 (NOT FOUND) since it was already removed. Some may argue that it makes DELETE method non-idempotent. It’s a matter of discussion and personal opinion.
If the request passes through a cache and the Request-URI identifies one or more currently cached entities, those entries SHOULD be treated as stale. Responses to this method are not cacheable.