Problem with setpoint on offboard mode

I have a problem with my offboard mode. I am controlling a Tarot 680 with the vision mode (SLAM).

Flight seems to be ok, but when I takeoff the pixhawk controller send a 900us commmand to ESC which shutdown the motors. This behavior doesn’t block the takeoff of our drone, but something failed to takeoff due to that.

I would like to understand what is causing that? Sometimes the command of 900us is not send and flight go really more smooth.

Here’s a log file with the 900 us cmd :

Here’s a log file without the 900 us cmd :