When my Outlook calendar gets invited to an event from a Google calendar, the event that gets created on my Outlook calendar has a different iCalUID from the corresponding event in GCal.
However, the ID is preserved when my Google calendar gets an invite from Outlook. This makes me think that Outlook is parsing the .ics invitation incorrectly and not preserving iCalUID.
This behavior defeats the purpose of the iCal UID - having a global ID for events across calendars.
Any insight on why this discrepancy is happening?