I also contacted the registry support e-mail with the same issue but maybe there is a solution outside of the official support.
I recently migrated the provider HanseMerkur/foreman to a new
organization in github at terraform-coop/foreman. This was done by
adding a final notice in the provider in version 0.5.2 and then on
Github by moving the repository to the new organization after which I
re-registered the new provider location with a new GPG key. What I
didn’t notice what that the provider downloads statically link back to
the old location.
So I forked the repository back to its old location but the GPG keys are
now gone so I created and registered another key for the release 0.5.2
and resynced the release. The hashsums are apparently cached so that
didn’t work.
According to the documentation the re-sync repository function should add the webhook back into the repository. But I assume the it adds the webhook to the original repository via id which is now under new ownership. So new releases like 0.5.3 are not added to the list and re-syncing probably also works on the repository id and scans the new location instead of the old one.
Is there anything left I could I try?