Siri Suggestions for calendar items based on emails or apps are pretty neat. I just don’t understand this mess, though:

• Blue is my personal calendar, yellow the suggestions. For all four flights my Mac showed a suggestion that was 100% identical to existing items on my calendar.
• These items came from accepting the Siri Suggestions on my phone several days before taking this screenshot. I waited to see if this was just a delay in some sync.

Why does it not realize that these are exact duplicates? Why do I even get Found in Apps suggestions on macOS? The app in question here only exists on my phone: I don’t have the Lufthansa app on macOS, I’m pretty sure they don’t even have a Mac app. So the suggestions are synced across platforms – but shouldn’t that make it even easier more possible to detect that I have already accepted them?