New one. If I build a cluster, add a virtual machine, then create a new user and add them to the cluster, that user cannot see the vm that was created?

I looked in the Harvester UI and don't see a way to manage users. Are you asking about Rancher users after importing your Harvester cluster in Rancher?

If you use Harvester only, it doesn't support user management. If you use Rancher together, may you share the Rancher version? I can test in my local environment.