Based on your settings, events might not appear on your calendar until you respond to them or confirm that you know certain senders.
These senders include:
People who are not part of your organization
People who are not saved in your contacts
People you haven't interacted with before
Here is how you can update your Google Calendar settings:
1. On your computer, open Google Calendar.
2. At the top right, click Settings:
3. On the left, under “General,” click Event settings:
4. Select an option;
From everyone: All invitations are automatically added to your calendar:
You are also encouraged to include a note in the summary window of the booked appointment to check whether an invitation has appeared in the email inbox and calendar. What's more, if the email invitation shows an unknown sender, it's worth encouraging the client to add the consultant's email address to trusted addresses.