Hi Zendesk Support,
According to the comments here, if a customer requires a callback but waits>60 min for it, they will not be connected to an agent automatically but a new Zendesk ticket is created for callback later https://support.zendesk.com/hc/en-us/community/posts/4645654279706-Call-Back-Feature. I noticed the ticket system info: queue callback request: expired, but no inbound call created in the call table. Is it because they required a callback so no inbound call has been created? Thanks!