Android 4.1.2 notifications not arriving when screen is off

[Frodonne]

Hi there! My name is Juan, im from argentina, and im the owner of a Razr i (XT890). I bought from the telco CLARO, and got it updated to JB with a deploy from them, after a few months of having it in my power. Since the day I did it, my whatsapp and gtalk notifications are not arriving properly. When i switch screen off, i get them normally for about 10 minutes. After that I stop getting them until i turn my screen on again. Someone told me this is a widespread issue on JB 4.1.2, but i have not been able to find anything on android forums, so i ask here. Im currently running this version:

982.50.25005.XT890.AmericaMovil.en.AR

Anything you can do to help me?