Azure Artifacts is returning 404 for some of the public npm packages
Looks like this is a permissions issue. Can you please check to make sure that you (and other developers trying to pull from upstream sources) have Collaborator (or better) permissions?
Source: https://docs.microsoft.com/en-us/azure/devops/artifacts/feeds/feed-permissions?view=azure-devops
In my case I had to allow project scoped builds. Our Project Collection Build Service was already set as a contributor. But in the navigation menu under permissions there was an ellipses and when clicking it it gave me the option to select Allow project-scoped builds.