Updating an event which is shared with Google users

It's clear to me that Apple Calendar and Google Calendar do not shake hands. For example, when I use my Apple account to invite a Google user to an event, they have click a Google Accept button to add it to their Google Calendar then click Apple's Accept button to alert me that they've accepted the event.

However, if I update the calendar event in Apple Calendar, Apple sends a new email saying the event has been updated with a new (Apple) Accept button. If they click that button, I am alerted that they have accepted the update. However, there is no way for the invitee to update their own Google calendar. It is not updated by clicking Apple's Accept button. Even manually changing the event in Google Calendar is impossible. Google displays an error saying "You can't reschedule this event. Propose a new time."

Is anyone familiar enough with with how shard Apple and Google calendar events interact to help?