Hi César,
I am fine, thank you. How are you?
Strange case, I am really thinking what is best to do. According to me you have followed the right procedure and also it is a standard field available in one of the field pools. I would expect the field to be delta relevant. If it would have been a custom field, then it was a different story.
I suggest to run report RMCEXACT (please refer to SAP Note 766603 - Activation problems with extract structures). I am curious what the report says about the affected extract structure.
Also useful can be to make a small modification to the communication structure, to activate it and then repeat the steps you executed before. Just to be sure.
Best regards,
Sander