I found this post about something similar: Provisioning of server works fine deployment fails for production trellis ssh fails .
I followed the steps to update the ssh config file and add the key to the ssh agent. When I ran the command “trellis up” again the VM was built and is ready for use.
Update: With the VM “up and running” I then tried to ssh into it but the process would just sit there after running “vagrant ssh” so I assume this is NOT working correctly. Then I deleted the VM and re-ran “trellis up” and now I am back to the same issue as before where the "trellis up " process hangs at the default: SSH auth method: private key.