Can't delete images about reg HOT 5 CLOSED

/ # echo $REGISTRY_STORAGE_DELETE_ENABLED
true

/ # cat /etc/docker/registry/config.yml 
version: 0.1
log:
  fields:
    service: registry
storage:
  cache:
    blobdescriptor: inmemory
  filesystem:
    rootdirectory: /var/lib/registry
  delete:
    enabled: true
http:
  addr: :5000
  headers:
    X-Content-Type-Options: [nosniff]
health:
  storagedriver:
    enabled: true
    interval: 10s
    threshold: 3

reg --registry https://myregistry delete alpine@sha256:b56ae66c29370df48e7377c8f9baa744a3958058a766793f821dadcb144a4647
Deleted alpine@sha256:b56ae66c29370df48e7377c8f9baa744a3958058a766793f821dadcb144a4647

reg --registry https://myregistry delete alpine:latest@sha256:b56ae66c29370df48e7377c8f9baa744a3958058a766793f821dadcb144a4647
Deleted alpine:latest@sha256:b56ae66c29370df48e7377c8f9baa744a3958058a766793f821dadcb144a4647

reg --registry https://myregistry ls
Repositories for https://myregistry
REPO                TAGS
alpine              latest

2017/11/24 15:20:02 ref: sha256:4b8ffaaa896d40622ac10dc6662204f429f1c8c5714be62a6493a7895f664098

nwe-reg manifest openvpn:v0.0.1
{
   "schemaVersion": 2,
   "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
   "config": {
     "mediaType": "application/vnd.docker.container.image.v1+json",
     "size": 2059,
     "digest": "sha256:6a2e9a93fa6ffa47b83c32a7afb6fdff0fc1b765ef7c5a962e4e2e27d03a0c05"
   },
   "layers": [
     {
       "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
       "size": 1991435,
       "digest": "sha256:b56ae66c29370df48e7377c8f9baa744a3958058a766793f821dadcb144a4647"
     },
     {
       "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
       "size": 2487962,
       "digest": "sha256:500d7c908a09320a3ceb63b207aea199389dbecde18950363115287359ead8ee"
     }
   ]
 }

# nwe-reg -d manifest openvpn:v0.0.1 |grep "ref:"
[...]
2017/12/14 10:02:11 ref: sha256:fc785bb24e2b65fffff2ae72897d80c0c564100f167cfba08f114aaa7c4fd560