Unable to open appointment created with Windows Appointments API in Outlook 2016

Since 6th of September, I'm unable to open any appointment created with my UWP app using Appointments API in Outlook 2016. If I try to do this I get an error:

Sorry, we're having trouble opening this item. This could be temporary, but if you see it again you might want to restart Outlook.

Error code is 0x80070057 (MAPI_E_INVALID_PARAMETER). This issue applies to Office Outlook for PC only. My app was deployed using both Visual Studio 2015 and Visual Studio 2017.

I'm able to:

• create an appointment with Appointments API and open it in Calendar app/Outlook Web/Outlook on the mobile,
• create an appointment with Calendar app and open it in Outlook 2016/Calendar app/Outlook Web/Outlook on the mobile

Here is what I found:

• all appointments created with the API fails if I try to open them in Outlook 2016 (even very basic one, with just a subject test, empty body and 30 min of duration)
• the issue does not depend on the Windows version (same result with appointments created with previous version of the SDK on Windows 10.0.14393 - it worked until September 6th)
• I am able to open all appointments created before September 6th (regardless of the version of Windows or Outlook); appointments created after this date fails to open (checked on multiple PCs and calendars even on different Office365 tenants, fails even in Outlook 2016 on Windows 8.1)
• checked on different versions of Office 2016 (1708, 1707, 1611) - same results for appointments created before and after September 5th

Here is an issue on GitHub: https://github.com/Microsoft/Windows-universal-samples/issues/735

UPDATE I used OutlookSpy tool to look into the properties of the problematic appointment and it turned out that most of the appointment's properties are null.