Check if “Calendar to add appointments” is set in the calendar settings of the member who will be in attendance.
If the appointment is not linked to the Google calendar of anyone other than the owner, even if it is specified as a member to be present on the reservation page, please check the settings on the Google calendar side.
Appointment Settings > Add Invitations to Calendar
Add all invitations": the invitation will be added to the calendar without approval
Add only if received from a known user": Confirms notification by email and requires approval.