Problem to define Secure Connect Gateway in ECS

Hi,

We have added an ECS device in SCG gateway without problem (correct status in SCG)

But when we add SCG gateway in ECS (ECS / Setting ESRS ==> status Failed in ECS for that gateway.

We try to add definition in Xdoctor for a SCG gateway  ==>  connect timed out received.

So Just to be sure  waht is the bes way to add definition for ECS in SCG.  in documentation we see : 

 Configure the device to connect to secure connect gateway or add device from secure connect gateway user interface ==> so we add  device ECS inSCG but afte we have some problem ?

So any help is appreciate to understand why we encounter this problem.

Best Regards,

Didier