Helm repository returns 404 when accessed by Octopus Deploy

Summary

After pushing packages to a helm registry as described at https://docs.gitlab.com/ee/user/packages/helm_repository/ a 404 is returned when accessing from an External Feed in Octopus Deploy.

Steps to reproduce

1. Push a helm package via the curl instructions at https://docs.gitlab.com/ee/user/packages/helm_repository/
2. In Octopus go to Library -> External Feeds and add a new helm feed using the gitlab url hosting the registry from step 1
3. In an Octopus project process add a step to Upgrade a Helm Chart (stock Octopus Step Template)
4. Configure the Chart section of the Step Template to use the gitlab feed and a package in that feed.
5. Create a release in Octopus and Deploy.

Note Testing the external feed in Octopus is successful, it only fails when Octopus attempts to retrieve the package.

What is the current bug behavior?

404 error is encountered during Octopus Deploy.

What is the expected correct behavior?

Helm chart should be retrieved and target should be upgraded.

Relevant logs and/or screenshots

Failed: Octopus Server
Error    |       Helm failed to download the chart (Status Code 404). Reason: $Not Found