API Returns 429 Behind a CDN? Trace Rate Limits and Configure Retry Backoff Only CDN IPs in Your Logs? Restoring Visitor IPs in Nginx with Trusted Proxies CDN Certificate Issuance Failed? Troubleshooting CAA Records, CNAMEs, and Domain Validation WebSocket Disconnects Every 60 Seconds Behind a CDN? Troubleshooting Nginx Timeouts and Heartbeats File Uploads Return 413 Behind a CDN? Troubleshooting Body Size Limits, Nginx, and Chunked Uploads ERR_CONTENT_DECODING_FAILED After Enabling CDN Compression? Troubleshooting gzip, Brotli, and Response Headers SSE Responses Arrive All at Once Behind a CDN? Troubleshooting Buffering and Timeouts CDN HTTP/3 Slower or Unreachable for Some Users? Troubleshooting QUIC, UDP 443, and Fallback CDN Cache Hit Ratio Dropped? Troubleshooting Query Strings, Cookies, Vary, and Cache Keys Website Returns 403 After Enabling a CDN? Troubleshooting WAF Rules, Origin Allow Lists, and Hotlink Protection