ESC/motors not working

I have a Pixhawk Pro. I tried to calibrate using it but the ESC never goes into calibration mode(no beeps, only when I press the switch to arm). I tried everything, test motors, calibration, etc…

To be sure that I was not doing something wrong, first I tested it with a small drone and works perfectly.

I’m using the FREERCHOBBY ESC (DC 50-100V, Max input supply voltage: DC100V, Lipos:12-24S):

datasheet_ESC.pdf (81.7 KB)

And I measure the main PWM OUT1 and It’s seems to be ok:

do you have any ideas?