ESC calibration with new Transmitter and receiver

Good day all

Drone info:
FC is Pixhack V3x
FW 4.05
ESC 40A Hobbywing BL-Heli
ESC selection set to NORMAL

I usually used the manual ESC calibration which always worked like a bomb !! And its easy
and quick.
Just for the record, here s a link to that same procedure:
( look at the video )

I am however using a completely new transmitter / receiver combination. This causes the
sky-unit ( on the drone ) to take a while to present the signal to the RC input of the FC.
( I suspect this is the problem ). Therefor, by the time the FC needs to make a decision to
boot up normally or to go into ESC calibration mode, it does not see full throttle on its input
and therefor continues to boot up normally . Which means it never enters ESC calibration
mode. This is not a problem of the software and its not a problem of the FC. It simply is
a fact … because of the time the sky-unit takes to boot. I have to live with this because it is
a very nice transmitter / receiver system.

I still need to calibrate my ESC’s. So I turned to the Semi-automatic method. Using Missionplanner,
I click the “Calibrate ESCs” button on the ESC Calibration page of MP and it does indeed change
the ESC CALIBRATION parameters to 3. I then do as the link above explains but it just keeps
on … 2beeps … 3 beeps … 4 beeps … 2 beeps … 3 beeps etc .etc ( I use 4S battery )
LED flashing blue …red … yellow ( Im sure theres a yellow in there somewhere ) It never gets to the LONG beep.

Anyone perhaps have a suggestion ?
Thank you all !