How to Fix Cloudflare 521 Error with Firewall Settings - Cloudflare SSL Full vs Flexible: Troubleshooting Mixed Content & Errors-Fix Nginx 502 Bad Gateway in Docker Due to Memory Limits
Likely symptom
Likely cause
Safe rollback
Verification route
- Repeat the original action, not only a simplified test case.
- Restart the app or reload the service after configuration changes.