Chatbot reply returns 201 but is invisible under user messages

Hello Zoom Support,

Our chatbot receives @mentions in a Team Chat channel successfully.

POST /v2/im/chat/messages returns HTTP 201 when using reply_to,
but the reply is invisible under the user's original message.
Replying to the bot's own messages works correctly.

We verified that to_jid is the correct channel JID and reply_to
matches the original webhook message_id. The same issue occurs
with direct API calls outside n8n.

App ID: 8gk__loKQnSZAccUPR3cYQ
Channel ID: 7939393e8d5d44f19b54be68dd0bff6f

Failed request:
Time: 2026-10-15 06:07:21 UTC
reply_to: 8c2c7031-a24a-485a-88ab-bcd468791659-W_f66578e1-N
Returned message_id: 20261015060721897_N9GF7fX_aw1
Tracking ID: BOT_4d2a4909082b4a1e9a0687dad4a94f9b

Successful bot-parent reply for comparison:
Time: 2026-10-15 01:59:05 UTC
Tracking ID: BOT_606af2096e684b08afd80b89887a26b8

Please trace why the user-parent reply returns 201 but does not
appear, while the bot-parent reply works.

Thank you.