My phone's an LG-E460. Sometimes, when I lock my phone, I stop getting most chat notifications (Whatsapp, Telegram, Google Hangouts...)
Happens specially often with Whatsapp, though. I'm talking to someone and if they take a long time to answer I lock my phone and keep doing my thing. No notifications. After a while, I check on them and BAM! 20 unread messages from ten minutes ago. When using Web Whatsapp I have to keep constantly unlocking my phone so it doesn't desync ("Connection with phone has been lost" pops up constantly).
This has been driving me insane. I've started to check on my phone even if I have no notifications just in case. What should I try?