PX4 altitude problem

I use pixhawk4 with PX4 and LidarLite for the primary height sensors.
But I try to climb up and it stuck at 19m above the ground.
I try Position mode or Altitude mode and still can not climb over it.
I don’t have the Geofence Max Alt setting.
And I set the RTL alt to 15m. (I’m not sure it matters)

Is there any parameters limiting the maximum altitude?
Or anything I did wrong?