oc-mirror v2 disk2mirror fails to read image manifest with "manifest unknown" error

Issue

• Attempting to run oc-mirror -c ImageSetConfiguration.yaml --from file:///path/to/mirror docker://registry.example.com/repository --image-timeout=2h --retry-times=10 --retry-delay=120s --cache-dir=/home/user/workspace/oc-mirror --v2 results in the following error, when trying to mirror the operator index images.

  collect catalog "registry.redhat.io/redhat/redhat-operator-index:v4.18": get manifest: error when creating a new image source: reading manifest v4.18 in localhost:55000/example-redhat-operator-index: manifest unknown