Handshake.parse used endsWith("\r\n\r\n") to detect a complete request, which is only true for header-only GETs. Any POST with a body never matched, so parse returned null forever and the handshake worker hung until the connection's idle timeout. Symptom in zlay: the reconnect cronjob POSTs requestCrawl through the same socket as the firehose. Every request stalled, no PDSes were re-announced, and the job hit its activeDeadlineSeconds. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>