Published app works internally but external redirect loop persists

Scenario

An app works internally, but external users are caught in repeated redirects when browsing through the firewall or proxy.

Recommended Resolution Path

1. Inspect host header handling, TLS offload, and upstream redirect logic together.
2. Test from outside the network with a clean session so cached cookies do not mislead.
3. Check whether the backend believes it is serving HTTP while the edge serves HTTPS.
4. Fix the canonical URL path rather than masking the loop with ad hoc rewrites.

Technician Notes

Confirm the result, document the root cause, and record any preventative action worth standardizing.