I'm using AM 1.9.0.346, but have actually experienced this problem through multiple builds.
On my exchange account, when I have a recurring event that I change in Outlook (e.g., change one date of the recurring event to another day), the resulting change shows up in the Android calendar on the correct day and starting at the correct time, but the length of the event is incorrect. It could end up being 30 minutes or 4 hours, but never the actual length, which is usually 60 minutes.
The issue exists in the Android stock calendar, Digical, and Calendar+. When I look at Nine's entry in the same calendars, it's correct, so it seems it's the way AM is processing the change in the recurring event. By the way, this occurred in Android 6 and now Android 7.
