Phone call log webhook events not delivered — SMS events work fine on same subscription

I have a Server-to-Server OAuth app with Phone webhook subscriptions. SMS events (phone.sms_sent,
phone.sms_received) fire correctly and deliver payloads to my endpoint immediately. However, call
log events never fire — no requests reach my server at all.

What I’ve tried:

  • Verified all Phone scopes are enabled (366 admin-level scopes)
  • Confirmed endpoint URL is correct (same one receiving SMS events successfully)
  • Re-validated the webhook endpoint
  • Deleted and recreated the event subscriptions
  • De-authorized and re-authorized the app
  • Made multiple test calls (inbound and outbound) and waited 24+ hours
  • Confirmed call logs appear in the Zoom admin portal
  • Confirmed call recordings are enabled at the account level

Events subscribed (all on same subscription):

  • Caller call log is completed — NEVER fires
  • Callee call log is completed — NEVER fires
  • Call recording is completed — NEVER fires
  • Call recording transcription is complete — NEVER fires
  • Voicemail is received — NEVER fires
  • Voicemail transcription is complete — NEVER fires
  • SMS received by Zoom Phone — WORKS
  • SMS sent from Zoom Phone — WORKS

Environment:

  • App type: Server-to-Server OAuth
  • Account type: Zoom Phone Pro (Business)
  • Endpoint: Supabase Edge Function (HTTPS, valid SSL, publicly accessible)
  • Webhook validation: Completed successfully, token verified

The key detail: SMS and call events share the exact same subscription URL, same app, same OAuth
credentials. SMS works perfectly. Call events produce zero webhook deliveries — nothing in my server
logs, not even failed attempts.

Question: Is there a known issue with call log webhook events not firing? Is there an additional
setting or entitlement required beyond Phone scopes to receive call log events? Any help
appreciated.