Header modification conflicts between CrowdSec and Authelia cause silent failures

When both CrowdSec bouncer plugin and Authelia middlewares attempt to modify headers in sequence, Traefik v3's stricter header handling causes silent failures. CrowdSec adds custom headers for tracking decisions, while Authelia manipulates X-Forwarded-* headers and authentication state headers. The competing modifications corrupt the request, causing timeouts without explicit errors.

Enable debug logging in Traefik static config (log.level: DEBUG) to observe request flow through middlewares. Avoid chaining middlewares that both modify headers and inject redirects. Separate concerns by moving IP filtering to network layer and keeping only authentication middleware in Traefik.