I've had my note 5 for a month now, it's been great but i've started to notice an issue that most of my notifications are delayed now on Wi-Fi ONLY but everything is fine on cellular data. This happens mainly when the phone has been sleeping for over 10/15 minutes. The issue is most noticeable with whatsapp/ gmail and facebook notifications. Doesn't seem to be a router problem since i've tried 3 different routers now. Has anyone else had this issue or know of any fixes?