Disarmed by lowest throttle stick position

Hello all,

I’m flying a quadcopter with stabilized mode.
I’m experiencing that the quad copter is disarmed by lowest throttle stick position for several seconds.
Is it a default setting? If so, do you know the reason for that?
If I don’t want that setting, how could I change it in QGC?

this seems to be the recent px4 firmware behavior. Probably good for beginners, but really confused experienced pilots.