Outlook not showing events created on a delegate calendar via EWS

[guidedways]

I've noticed Outlook uses a mix of EWS and the new Microsoft API, so I'm not sure if this is a bug, but basically:

1. New calendar events created on a "shared calendar" (with read/write access) in a 3rd party app using EWS, only shows up in other apps that use EWS but not on Microsoft Outlook. e.g., create event in BusyCal → shows up on Fantastical (and vice versa), but not in Outlook. Only the owner of the calendar is able to see these events.

2. Event created in Outlook however, shows up in all apps. What's going on here? This has only recently started happening.

I realize EWS is in maintenance mode but this is some breaking change affecting a lot of our enterprise users.

[guidedways]

I can confirm this bug isn't there in Outlook v15, but only in v16.6. Who do I reach out to?

[SO-amit-singh]

I am also facing the same issue. Is this expected behavior?