No server response on Identify (Also, is there a 'validation' form for the Authentication string for 'Identify'?)

[mel_rode]

Guys,
some background: I'm working on c++ boost::beast websocket code to connect up with OBS server. Relatively new to c++, too.
Tick 1: I get the handshake authentication salt and challenge:
{"d":{"authentication":{"challenge":"6MWN0sRhcdpP3xzOFE0c2zVUQ9US4SohP9VkMV86GuY=","salt":"vLdU4GyBfrx7y3M35q+oOCw+elCcWZ8rx6DOCcogx74="},"obsWebSocketVersion":"5.1.0","rpcVersion":1},"op":0}
All good.
I churn out an authentication string and send it back to the server:
Here's a log entry:
[obs-websocket] [debug] [WebSocketServer::onMessage] Incoming message (decoded):
{
"authentication": "1d10139ca4bee22a5aa49d528891656be755580ab1ce1399906f357378df5ee8",
"eventSubscriptions": 33,
"rpcVersion": 1
}
But the server doesn't seem 'eager' to reply?
Here's (part of the) server's log:
15:26:24.159: [obs-websocket] [WebSocketServer::onOpen] New WebSocket client has connected from [::ffff:127.0.0.1]:56929
15:26:24.160: [obs-websocket] [debug] [WebSocketServer::onOpen] Sending Op 0 (Hello) message:
15:26:24.160: {
15:26:24.160: "d": {
15:26:24.160: "authentication": {
15:26:24.160: "challenge": "6MWN0sRhcdpP3xzOFE0c2zVUQ9US4SohP9VkMV86GuY=",
15:26:24.160: "salt": "vLdU4GyBfrx7y3M35q+oOCw+elCcWZ8rx6DOCcogx74="
15:26:24.160: },
15:26:24.160: "obsWebSocketVersion": "5.1.0",
15:26:24.160: "rpcVersion": 1
15:26:24.160: },
15:26:24.160: "op": 0
15:26:24.160: }
15:26:24.216: [obs-websocket] [debug] [WebSocketServer::onMessage] Incoming message (decoded):
15:26:24.216: {
15:26:24.216: "authentication": "1d10139ca4bee22a5aa49d528891656be755580ab1ce1399906f357378df5ee8",
15:26:24.216: "eventSubscriptions": 33,
15:26:24.216: "rpcVersion": 1
15:26:24.216: }
15:26:29.217: [obs-websocket] [WebSocketServer::onClose] WebSocket client `[::ffff:127.0.0.1]:56929` has disconnected with code `1006` and reason: The closing handshake timed out