when i create a repeated event (once a week) and then update just one instance to a diferent time (since I want to have it at different time during that week), no invite update is sent and so my colleague does not have it updated in his calendar. in my google calendar I see it updated just fine.
same happens when I am deleting an event or series of events from the google account calendar. in google calendar thsi happens but no message is sent to invited people.
when I do the changes directly in google calendar, it all works.
update from single to multiple (repeated) event works fine and an update is sent
it is also interesting that for this calendar the messages do not go through outbox but are directly sent so I cannot even trace them easily without asking my colleague to check his email