Magellan OpenText deployment on generated VM, can't get node details in deployer

I've created a template instance of OpenText v24.3, and I can access the base instance (used for creating the template) just fine.

However, with the new instance created from the template, I can have the deployment/installation program connect to it, at least enough to get the instance name. However, when I open the deployment in the deployer, I get an error "Failed to get node details."

In the logs, I see an IllegalArgumentException (which causes an HTTP 500).

What is going wrong, and how do I fix it?