Was your account linked with IFC in-app at the time of the issue?
Iphone 7 +
In this new version I found the issue with activating AP for all types of aircraft models. The issue is that once airborne, immediately after AP being activated, depending on the control sensitivity of pitch you set, the aircraft may be very unstable, manifesting in immediate extremely large pitch angle that leads to stall, or, immediate sink.
I tested this across all types of aircraft and found that it happened to them all.
In general, if the pitch sensitivity is set low, then the aircraft is mostly likely ran into stall. However, I found that manual adjustment of trim may help this issue partly.
Steps to reproduce
*_Pick any type of airplane and do normal take off procedure
*_Active AP once airborne
Large pitch angle or sink