Test the application directly from the proxy host, then through the public URL:

curl -i http://127.0.0.1:8080/healthz
curl -I https://kaya.example.com/login

Redirects to an internal URL point to an incorrect Base URL or forwarded protocol. 400 host failures point to Allowed Hosts. Wrong client IP or non-secure URL detection points to FORWARDED_ALLOW_IPS. SSH/RDP connection failure only through the proxy often means missing WebSocket Upgrade handling or timeouts. Upload failures may be proxy body-size limits below Kaya's configured value.

Verify Host, X-Forwarded-For and X-Forwarded-Proto; allow WebSockets; and compare the Site Administration current-request panel. Do not trust wildcard proxy peers to make the warning disappear.

See Reverse Proxies and Trusted Proxy Problems.