k3s Registries.yaml – How to Fix Parsing Errors

I have set up a k3s Kubernetes standalone server with a insecure private registry but k3s fails to pull images from it.
The registries.yaml file is set as documentation says. It is below.

mirrors:
  "registry.cube.local:5000":
    endpoint:
      - "http://registry.cube.local:5000"

The image is in the registry but k3s pods won't push them showing the error below:

failed to do request: Head "https://registry.cube.local:5000/v2/batch/manifests/v0.9": http: server gave HTTP response to HTTPS client

As per the registries.yaml configuration, that should not happen, because it is configured to use http. I went to checked the journal with journalctl -xn -u k3s.service | less to spot errors and I can see the below warning:

Oct 17 21:51:20 local k3s[25571]: I1017 21:51:20.401763   25571 event.go:294] "Event occurred" object="kube-system/registries" fieldPath="" kind="Addon" apiVersion="k3s.cattle.io/v1" type="Warning" reason="ParseManifestFailed" message="Parse manifest at \"/root/k3s/server/manifests/registries.yaml\" failed: Object 'Kind' is missing in '{\"mirrors\":{\"registry.cube.local:5000\":{\"endpoint\":[\"http://registry.cube.local:5000\"]}}}'"

I did lint the yaml file, and the conversion to JSON seems correct as per logs, so I don't think it is a file formatting thing.

I tried setting up a secure private registry, but that did not work because it also relies on the registries.yaml file configuration to work, and same error is shown with it.

I wonder someone sees the issue before I open a bug fot it on their github. It is really not making sense to me.