chartmuseum: Duplicate versions for same chart

We are seeing many duplicate entries in index.yaml for the same chart version. In some cases there are thousands of duplicates for the same version. We expect only one entry per version/tag.

ChartMuseum version: 0.13.1 Running as part of Harbor with multiple instances of chartmuseum and settings:

ALLOW_OVERWRITE=true
CACHE: redis
DISABLE_STATEFILES: "false"
STORAGE: amazon

Is there a concurrency issue that we should be aware of?

Example:

  - apiVersion: v1
    created: "2021-04-10T14:59:57.826535265Z"
    digest: 1cd815901d2166307de13a7632ae04c053256863e486276c3411b26f7a3b2f0c
    name: ourrepo
    urls:
    - charts/ourrepo-0.0.0-84ace941.tgz
    version: 0.0.0-84ace941
  - apiVersion: v1
    created: "2021-04-19T08:59:10.291630412Z"
    digest: 1cd815901d2166307de13a7632ae04c053256863e486276c3411b26f7a3b2f0c
    name: ourrepo
    urls:
    - charts/ourrepo-0.0.0-84ace941.tgz
    version: 0.0.0-84ace941