HTTPS routing fails when router only configured for HTTP entrypoint

Application works on HTTP but fails on HTTPS with 404 or connection errors. Router is only defined for 'web' entrypoint (:80), not 'websecure' (:443). Alternatively, router exists on websecure but missing tls=true flag or certresolver configuration. Clients attempting HTTPS cannot reach application.

Query Traefik routers API and check entrypoints field for router. Create separate router for websecure entrypoint or add websecure to existing router's entrypoints. Set traefik.http.routers.<name>.tls=true. Configure certresolver if using automated certificates. Test with 'curl -sS -D- https://<hostname>/' to verify TLS routing. Check certificate validity and SNI matching.