Why has my LG Leon with Lollipop stopped syncing apps?

[AC Question]

LG Leon with Lollipop sopped syncing apps

Hello, all of a suddon my wife's LG Leon with LP unrooted stopped syncing apps, so she does not receive any Whatsapp or Gmail notifications if she does not open the apps. I see WA messages are not even received until she goes to WA.
This happens both on LTE and on WiFi.

I checked that synchronization is enabled as always, I tried deleting caches for apps and Google Play Services, but this didn't solve the problem.

Please help!!

 

[B. Diddy]

Welcome to Android Central! Go to Settings>Data Usage, and make sure Restrict Background Data isn't turned on.

 

[Dario Piantanida]

No luck: it is already turned off...

 

[B. Diddy]

Any power saving modes or apps that are active?

 

[Dario Piantanida]

I would say no, nothing new, anyway. It seems the notifications are not always lost: some times they come through while others apps do not sync. I don't know where to look at...

 

[B. Diddy]

Try Safe Mode, to see if it's due to a 3rd party app: https://support.t-mobile.com/docs/DOC-21769. You won't be able to test WhatsApp in Safe Mode, but you should be able to test Gmail (or the stock Email app).

 

[Dario Piantanida]

Nope!

Even in safe mode I have to open GMail app and refresh message list to see the new messages...

 

[TrainerCary]

I have the same problem. I have tried reinstalling Gmail, still the same.