Zoom Webhooks not complete for certain meetings

Hello, 

we noticed that meeting join & left data is missing for some of the meetings.

1. The meetings are shown as greyed out in the zoom dashboard. unlike normal meetings which are shown as a link and opening the link opens the meeting details

2. We also have zoom events webhook configured. Its working fine for other meetings but for some of them its just sending `meeting.started` & `meeting.ended` events and not `meeting.participant_joined` and `meeting.participant_left` events. For some other meetings we are only getting `meeting.participant_joined` for half of the users and not `meeting.participant_left` event for the same user

3. Get past participants API also is of no use. It simply returns no participants or incomplete participants. I tried with multiple API endpoints `v2/past_meetings/{meeting_id}/participants` & `v2/metrics/meetings/{meeting_id}/participants?type=past` both are giving incorrect data.

anybody else is facing the same issue with zoom meetings ?

also, since Zoom can not be relied on getting participants attendance data, is there any other way thorough which we can figure out the accurate attendance data programatically ?