[BUG/Feature] Labels applied via /label/handleLabel don't sync to WhatsApp Business app

[carrosenavesmultimarcas-bot]

Hi team! Using Evolution API v2.3.7 (managed via Cloudfy).

Issue

When I call POST /label/handleLabel/{instance} with action: "add", the API returns 200 OK with {numberJid, labelId, add: true}. However, the label does not appear in the WhatsApp Business app for that chat.

Reproduction

1. List labels:

   GET /label/findLabels/{instance}
   

   Returns existing labels (e.g., id: "31", name: "HUMANO").

2. Apply label to a chat:

   POST /label/handleLabel/{instance}
   {
     "number": "5511999999999",
     "labelId": "31",
     "action": "add"
   }
   

3. Response: 200 OK

   { "numberJid": "5511999999999@s.whatsapp.net", "labelId": "31", "add": true }

4. Open WhatsApp Business app → check that chat → label is NOT applied.

Also missing

• No LABELS_ASSOCIATION webhook event fires when a label is changed via the WhatsApp app (only events firing are chats.update, contacts.update, messages.upsert).
• No API endpoint to query "which chats have label X" or "what labels does chat X have".

Use case

Building a chatbot that needs to know when a human takes over a conversation visually (via labels). Currently it's impossible to use labels for this purpose because:

• Labels applied via API don't reach the app.
• Labels changed in the app don't fire webhook events.
• No API to read labels per chat.

Expected behavior

• API calls adding/removing a label should propagate to the WhatsApp Business app.
• LABELS_ASSOCIATION event should fire on label changes from any source (app or API).
• API endpoint to fetch labels per chat.

Thank you!