impossible to delete stale hosted npm repository metadata

Create a npm hosted repo with id 'npm-hosted'.
Publish one package into it.
Hit the /-/all resource for this repo. Verify the published package metadata.
Delete the entire npm hosted repo using the repository Delete button.
Create another npm hosted repo with the same id.
Hit the /-/all resource for this repo again - you still get metadata about the first repo even though the new repo contains nothing.

Similar:
delete all the content from a hosted npm repo but leave the repo itself. Nexus still serves metadata about packages which do not exist. Expire cache on the hosted repo does not help.