Uncontrolled Climbing (& CTUN.DAlt Increase) in AUTO & LAND

I have a quadrotor with Pixhawk, APM:Copter V3.3.3. I have tested it in Stabilize & AltHold modes, works fine. Also tried switching to Land mode from Stabilize & AltHold, and the drone lands perfectly.

I wanted to try AUTO mode, as a first test I defined this mission based on the tutorials:

  1. Takeoff to 10 meters
  2. Loiter there for 5 seconds
  3. Land

As soon as I raised the throttle in AUTO mode, it started climbing VERY rapidly, and it kept climbing up until it was about 60 meters above the ground. I waited for like 10 seconds and it kept climbing, so I panicked & switched to AltHold mode. I’m a newbie pilot so I could not control it properly at that altitude and crashed!

I thought maybe it was a bug in my planned mission or a GPS glitch, so I fixed the copter and tried agian. This time with this mission:

  1. Takeoff to 3 meters
  2. Land

Again, same thing happened. This time, I switched to Land mode as soon as it went higher than 10 meters, but it kept climbing like crazy. Switched to stabilize and eventually…another crash.

I reviewed the logs, DAlt (desired altitude) keeps increasing even after switching to Land. It does not match my planned mission altitude (figure below). I have attached the log, can someone please help me with this?