BPM - Variables initialization when running a business process

BPM - Variables initialization when running a business process

I'm working on AMS with two business processes that are executed secuentially, I mean, the first process is executed and the other process is initiated by the first one through a message event.

I am starting the first process on AUP and it works fine, but the second one is presenting problems during the execution.

I checked the deployment on Camunda and for some reason the variables that I use on the second process are undefined, but the ones on the first process are correctly initialized. I've reviwed and there is no difference betwen a process and the other.

Is there any specification I must follow in order to do this?