Azure Migrate: Unable to add Hyper-V cluster as discovery source - Source validation failed - The given key was not present in the dictionary.

Question

Walking through the Azure Migrate guide, we set up the project in Azure, created the appliance, and began configuring it. Our goal is to leverage a "Servers, databases and web apps" project within our on-prem infrastructure to help our migration to Azure. We've also run the provided powershell script to prepare the Hyper-V hosts, seeing green "[Done]" messages for each step (script and steps found here)

Unfortunately, we've hit a roadblock when attempting to add our Hyper-V cluster as a discovery source in the Appliance Configuration Manager. We've tried different combinations of credentials, IP addresses, FQDNs and all always result in "Validation Failed. Source validation Failed. The given key was not present in the dictionary."

Is there a way to get more details on why the validation is failing or what key is not present in which dictionary?

We have tested adding another VM that is not in the cluster and are able to add that one successfully, receiving a "Validation successful" message fairly quickly.

Details of our on-prem environment:

• The Hyper-V hosts are running Windows Server 2022
• We have tried both domain and non-domain logins
• VMs are running a combination of Windows server operating systems, though generally are Windows Server 2022
• Hyper-V VMs are configured with an External network interface and configured with VLAN IDs/VLAN tagging
• The Hyper-V hosts are part of a cluster

Any help or guidance would be greatly appreciated. Thanks!