Hi Keith,
If you are deploying Azure migrate appliance for Vmware infra, then please note deploying appliance on vmware workstation won't help.
For vmware discovery and assessment, you need to deploy the appliance on vcenter and appliance should have connectivity to vcenter.
Trying to discover vmware infra using ESXi host, is not supported.
https://learn.microsoft.com/en-us/azure/migrate/common-questions-appliance