Here is some information from a help article within Protect that may need to be checked:
(from Help > Contents> Quick Start Information> Quick Start Info for Virtual Machines> Notes About Virtual Machine Templates)
During a scan, a template will be accessed using the VMware server credentials. Any individual credentials supplied for the template are ignored.
You should supply online credentials for any virtual machine template that will be included in a patch deployment process. During the patch deployment process the template is converted to a virtual machine and powered on -- VMware vCenter Protect will need the supplied credentials in order to access the online virtual machine.
When deploying patches to a virtual machine template, the following VMware server permissions are required in order to manage snapshots and to perform the deployment:
VirtualMachine.State.CreateSnapshot
VirtualMachine.State.RemoveSnapshot
VirtualMachine.Provisioning.MarkAsTemplate
VirtualMachine.Provisioning.MarkAsVM
You might also need to ensure that VMware Tools is installed on the template so we can fully interact with it. Make sure to try hitting the "refresh server" button within the machine group as well to see if this helps bring up the templates.