The multicopter is able to fly steadily in stabilized mode. However, when we switch to position mode, the multicopter suddenly climbs upward with full throttle even though the roll/pitch and throttle sticks are centered. What could be the root cause for this issue? I have attached the log files for your reference, thanks!
I think you should look into MPC_THR_HOVER parameter.
Can’t see it in your parameter list, but I know I was experiencing something similar until I messed around with it.