Sometimes I go into whatsapp and there are new messages but no notification in the top bar at all. Additionally, I have 2 smart watches (a pebble one and a cheap chinese one) and these both work for showing notifications but only for about an hour after installing the app, after that, nothing until I reinstall the specific app. I have told the phone not to optimise battery for the smart watch apps but it made no difference. I've had this happen with text messages, whatsapp, gmail and ring. It seems that this phone just has a real issue with notifications! Has anyone else experianced this sort of thing?