Heya folks, Ned here again. We've released our next set of features and fixes for the Windows Server 2019 Storage Migration Service, as part of cumulative update KB4580390 (Windows Server 2019) & KB4...
The SMS proxy not registering after being installed is an issue we're improving through an update to WAC in a few weeks. We'll soon automatically install the Proxy as well as re-register it if needed.
To fix that issue in the meantime, tho, you can either:
1. Go back and re-run Inventory (bleh)
2. Run this Powershell command on your orchestrator as an administrator:
Register-SmsProxy -ComputerName <name of your destination server> -force