@rhessinger,
Thanks for the detailed answer — that's helpful context, and to confirm: yes, by "bare username" we meant aduser1 (not aduser1@ourtest.local).
We applied everything you suggested on the V5 directory:
General tab: Domain = progetpoc.local, User name = Administrator, Password = (re-entered, confirmed saved)
Connection tab: Domain controller host = 172.17.0.1, progetpoc.local (comma-separated, IP first, DNS name second)
Advanced tab: NETBIOS name mapping = PROGETPOC=progetpoc.local
Used the Test User Directories tool as suggested (User Directory: "AD Test V5", Test Type: "Login with user name and password", User name: aduser1, Password: matching what we set for that account). Result:
Error: Connect Error
[Debug] Search string is "aduser1"...
We also checked our domain controller's own connection log during the test — it shows zero incoming connections, meaning ProGet isn't even reaching the network for this attempt. That suggests the failure is happening locally (e.g. during config/host parsing) rather than a real connectivity or credentials problem.
Our leading suspicion is the "Domain controller host" field's expected format — we entered both values as a single comma-separated string (172.17.0.1, progetpoc.local). Is that the correct syntax, or does that field expect one value per line, a different separator, or only a single value with something else supplying the second lookup? Want to make sure we're not just malforming that field.
Happy to send additional screenshots (any specific tab/dialog) if that helps narrow it down further.