Originally Posted by ArXane
N5 4.4.2. Straight Talk
It seems to be doing this the last couple of weeks. I get emails/hangout/email notifications fine on wifi, go to data, I can still use internet, but have to manually refresh email and hangouts to get new messages to appear. If I step back into wifi then everything starts working normally again.
In general your phone will update the server again to it's new IP to PUSH to. When you are on WIFI you are on your network and attached to whatever IP your ISP leases you. When you are on 3G/LTE or whatever your phone is getting a leased IP address from the carrier so the server will need to connect to your phone different. Since the server only updates once the client connects it wont know till the "heartbeat" is sent again or you manually refresh.
By default the heartbeat slows down after some time if it hasn't gotten any new messages in a while. So it may start off at 30 seconds then slowly drops down to 10mins (think this depends on the server). Once a new message comes in, the server pings your phone and tells it to connect for a new message and then your phone downloads and starts over the heartbeat again.
When you change IP addresses by going from WIFI to LTE it should update the server but maybe there is a bug or something that it's not working correctly. I haven't tested this scenario on my device so i can't be sure but that's how it's supposed to work.