Package Manager not showing versions of a package after NPM server maintenance

We host our own internal NPM registry for development packages. We did some maintenance recently that involved cleaning up old versions of a specific package. All versions were unpublished and then re-uploaded to the registry. They're definitely there on the server - we can see them in the NPM web UI and download via command line.

But now UPM UI is only showing one version of the package. It appears like there are no other older or newer versions of said package. But if I manually enter one of these "missing" versions into my manifest.json, Unity downloads it no problem!

I've already tried deleting the cache folder. But this seems like potentially some issue with Unity not correctly recognizing the versions of this package as a result of them being removed and re-uploaded to NPM. What can I do to repair what Unity Package Manager sees/displays?