Why my Samsung Galaxy S6 Edge no more notify me of new notifications when screen is locked?

[Salman89]

I bought S6 Edge when it came out, everything was going fine until may be 2months ago it stopped notifying me of any new emails, skype calls, whatsapp msgs/call, viber etc almost all social apps when screen is locked.

When I unlock the screen, then many notifications pops up ranging from few mins to few hours. My phone decides whether to notify me as it gets any new msg/email or notify me after an hour or two. It's frustrating, I have to keep unlocking the phone to see if any new msgs/texts pops up. It only notifies me of regular cellular calls and messages on time.
I have tried uninstalling/updating/disabling all these apps but in vain.

E.g. if my friends calls me on skype, I don't get any notification, when i open Skype app by any chance then i know there are e.g. 5 missed calls. Same is with whatsapp/viber/slack/snapchat etc.

I have tried clearing cache and restarting phone and everything except resetting it (which I don't want to).

Is there a way I can fix this without factory resetting it? Thanks.

 

[B. Diddy]

Welcome to Android Central! Make sure you don't have any power saving options turned on--they might be turning off the phone's data connection or push notifications while asleep.

 

[Salman89]

Thanks for reply but I have checked phone power saver is turned off, is there anything else i can try to fix this?

 

[B. Diddy]

Also, no other 3rd party battery-saving apps installed?

When you said you cleared cache, do you mean the app cache, or the system cache partition? If you haven't cleared the cache partition, it's worth trying: https://support.t-mobile.com/docs/DOC-21095