Answer
First install the Print Agent as a Windows service, specifying a domain user account that's allowed to log into the domain and has access to the target printers — this step is required before the connection will work at all. Start that service; once it starts successfully, the tray icon should turn green, and only then will monitoring show a connected status. The ID field itself can be any name — it's just a unique identifier, not a hostname or IFS Instance ID that needs to match anything specific. Make sure you enter the IFSPRINT password in plain, decrypted text when configuring the connection (it gets encrypted automatically once saved), and separately confirm the IFSPRINT database account itself isn't locked, since a locked account will also prevent the connection from succeeding.