I use Samsung Galaxy Note 4 SM-N910C that is rooted and running official marshmallow. All was going well for 6-7 months. But suddenly I am not getting push notification from the facebook app for the last month. The only time I am getting push notification from the facebook app when I try to login from another browser and a code is needed from code generator. Push notification from other apps, email, instagram etc are working. I have tried clearing data of the app, turning off platform, uninstalling greenify. Butnothing worked. What to do now? Please help.