Hosted apt repo index doesn't refresh on distribution change

When the distribution field for a hosted apt repo is changed, the repo metadata is not regenerated to reflect this. This does not happen automatically, nor when clicking "Rebuild index".

Workaround is to upload something new to the repository, at that point the new metadata appears correctly below metadata/dists/. But the dir for the old distribution is left behind there too, requiring manual removal.
 
I think changing the distribution field should take care of all this automatically.