⚠️ Your browser can show the proxy IP while UDP traffic takes a completely different route.
WebRTC and HTTP/3 both use UDP. Chrome doesn't use SOCKS5's UDP relay, so configuring SOCKS5 in the browser doesn't route UDP the same way.
Three possible outcomes:
🟢 TCP fallback through the proxy: direct UDP blocked, application uses TCP
🔴 Bypassed: UDP exposes the real source IP
🟡 Suppressed: UDP never reaches the destination
Number three is the trap. Disabling WebRTC prevents a leak, but it doesn't prove UDP is proxied, and a browser with zero ICE candidates stands out on its own.
🔎 On Chrome with SOCKS5: set WebRTCIPHandlingPolicy to disable_non_proxied_udp, then disable HTTP/3 and QUIC. You're choosing TCP fallback deliberately, which is the right call.
None of it helps if the proxy itself isn't reachable with the right credentials. Free Proxy-Check here: https://proxy-seller.com/tools/proxy-checker/