Hi @guyk,
Glad to hear that fixed your issue with the Docker hub connector. When it comes to "Attempt to search", this options does work on Microsoft's container registry, GitLab's container registry, and Google Cloud (gcr/k8s). It only actually affects searching for images though. When it is unchecked, it just requires exact image name searches.
The manifest error is definitely annoying, unfortunately, Docker itself filters out all returned errors and just displays that "not found: manifest unknown: manifest unknown" message. Along with that, when it comes to querying other Docker registries, they throw a lot of errors instead of just returning an empty dataset when an image is not found. That makes it hard to produce meaningful entries into our logs.
As for the Azure container registry. Are you using a public or private registry? One thing we have noticed is the Azure container registry can have multiple package types mixed into it. When you mix package types, ProGet has a hard time using that registry. If you can provide us with an example, we can quickly debug it and let you know what is wrong with the connection.
Thanks,
Dan