Why am I missing a meeting participant in “Approval Status”?

Why you cannot see all meeting participants in "Approval status"

This can happen because the meeting participant was not a team member before the approval for the item was turned on. Click on “Yes, add users” to add the meeting participant to the list.
 

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Status for approval

 
It can also happen because the meeting participant has not yet activated their invitation to FirstAgenda and thereby is not an active user. This needs to be done before a meeting participant can be added for approval in FirstAgenda.
 

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Missing approval