I have not flown my quad in couple weeks. I installed a new gimbal and went flying today..
The quad was very erratic. I even tried flying it with the gimbal completely plugged out and power off. Did not fly confident at all.
I noticed one of the times when I changed out battery and powered back on quad. When I tried to arm i got an error " ARMING:ALTI DISCREPANCY " on mission planner, I did not remember the exact message but I am pretty sure that was it. The message disappeared after couple seconds and then I was able to arm.
Anyway, I proceeded to fly ( I was in a controlled enviroment with no houses around, just open fields ).
I fly the quad around for about 1min, then all of a sudden the quad JUMPED in altitude a few feet.. Ofcourse I thought it was going to fly away, but I was still able to bring it back down.
I fly in POSHOLD/HYBRID mode.