As of Zoom Room version 5.1.2 the “echo on/off” commands no longer appear to be functional, all commands are echoing back even when “echo off” is sent.
Even more problematic, the echo’s can end up in the middle of a large JSON responses, making separating JSON and echo’s difficult.
Again—Thanks for your patience while we try to get this (and your other question) answered for you. I’ve followed up with our team and should have an update for you soon.