Typing indicators not triggering in Genesys Cloud Web Messaging Guest API

Could someone explain why my manual POST requests to the Genesys Cloud Guest API for typing indicators are being silently dropped?

I am building a custom Vue 3 supervisor dashboard that needs to mirror guest activity in real-time. While the standard Web Messaging SDK handles this internally, I am bypassing the SDK for a specific testing tool that requires direct API control. I can successfully send messages to POST /api/v2/webmessaging/guests/{guestId}/conversations/{conversationId}/messages and they appear immediately in the agent UI. However, when I attempt to send a typing indicator via POST /api/v2/webmessaging/guests/{guestId}/conversations/{conversationId}/typing, the request returns a 200 OK status, but the agent sees nothing. No “User is typing” bubble appears. The read receipts behave similarly.

Here is the payload I am sending:

const typingPayload = {
 event: 'typing',
 timestamp: new Date().toISOString()
};

// Using the same token and headers as the successful message POST
await fetch(`/api/v2/webmessaging/guests/${guestId}/conversations/${conversationId}/typing`, {
 method: 'POST',
 headers: {
 'Content-Type': 'application/json',
 'Authorization': `Bearer ${authToken.value}`
 },
 body: JSON.stringify(typingPayload)
});

I have verified that the guestId and conversationId are correct because the message endpoint works flawlessly with them. The network tab shows the request completing successfully with no errors. Is there a specific configuration flag on the Web Messaging channel or the application that needs to be enabled to accept these events via the REST API? Or is this functionality strictly tied to the WebSocket connection established by the SDK client, making REST calls invalid for this specific event type? I am looking for a code-level solution, not just a config check.