Plane disarms in midair when switching from STAB to AUTO

Hello all,

During a relatively standard flight today, our plane took off and entered STABILIZE mode. Around 12 seconds later, we toggled AUTO mode with a mission that has been flown previously. Upon entering AUTO, the plane disarmed in midair and resulted in a crash landing. The battery health should have been strong and the plane was very close to the ground station and transmitter. No issues were apparent when arming the craft either. Does anyone have an idea as to what happened? After analyzing the flight log we believe the cause is related to an odd barometric altitude reading, but we cannot confirm nor can we explain why this error happened.

Linked is the log for the flight:

Thank you!

Iā€™m not sure how you originally armed the plane, but there is an arming switch set up on RC6. A moment before the flight mode was changed to Auto RC6 cycled from low to high and back to low. This change back to low would have triggered the disarm. This event is also consistent with the disarm message in the log.