Default PROBLEM better battery stats and whatsapp notifications

hi guys,
i'm having a strange issue.
i have a m7 with the last firmware (4.4.3) and viper 6.2.1
yesterday i installed "better battery stats" and all was ok but today i faced an issue.
if a lock my m7 whatsapp notification won't come until i unlock it.
firstable i uninstall better battery stats but i'm still having the problem.
can anyone help me?