"Version <version> for package <package> not found" error in "security" column in package list

[BasementCat]

I have added several private packages from GitHub to an organization hosted on repman.io; and while this works fine for a while, eventually I get the error noted in the title of the ticket when hovering over the "error" label in the security column in the package list, and the packages are no longer installable via composer. This is occurring even with packages that have not been updated - literally nothing has changed, no code has been pushed/tags changed/etc, the code associated with the package simply disappears from repman.

If I log in and manually sync the package, this does resolve the issue. However, having to do this on a regular but unknown schedule in order to avoid deployments breaking is not sustainable, especially as the number of packages grows.

This may be a duplicate of #438 if repman.io is running largely the same code, however that was filed specifically in reference to a self-hosted repman instance.