Debugging Filestash 'Invalid Account': How Response Time Led Me to a Swapped Config Field

The Problem Filestash's passthrough auth returns "Invalid account" on login. The backend is configured to forward credentials to the local SSH server (OpenSSH on the same machine). SSH works fine when tested directly. Password auth is enabled. SYST INFO [auth] status=failed user=myuser backend=sftp err=Invalid+account HTTP 307 POST 4.7ms /api/session/auth/?label=sftp Environment: Filestash running in Docker (bridge network 172.20.0.0/16) SSH server on host: 192.168.1.x:22, listening on 0.0.0.0:22 UFW active on host identity_provider.type = passthrough, attribute_mapping.related_backend = sftp Diagnostic Step 1: Read the Response Time Before touching config, the response time is the first clue. Time What it means < 5ms Pre-connection failure — params missing/invalid, DNS failure ~5–50ms TCP connection refused (immediate RST) 100–500ms SSH handshake + auth failure (wrong password) 3000ms+ TCP timeout (UFW DROP, no route) 4.7ms → we never attempted a TCP connection. The error is thrown