Events added on iCalendar are not showing up on Google Calendar. Why?

The reason why you are not seeing the new events you add from iCalendar on your Google Calendar online is likely happening because you are not adding events to the correct calendar. In other words, the value of the “Calendar” field within Add Event is not really set to your Google calendar. For example, it might be set to one of your iCloud calendars instead.

Please note that you may set a default value for this field through Event Defaults screen (can be accessed from iCalendar Settings). If you set a default value, that default calendar will be auto-selected for you every time you add a new event.