I've been using PubNub to send push notifications to mobile devices. On iOS everything is working fine. At first it was working on Android as well. But now I'm seeing some strange behaviour. My Nexus 5 stopped receiving GCM messages all of a sudden. Even though my calls to the API to enable push notifications are always successful. I've tested it with a Samsung Galaxy S5 and it is working on that phone as well, but the Nexus 5 still doesn't receive the notifications.
I've taken a look at the API to check to which channels a device token is registered too. And I found out the following: Whenever I start my app and the Nexus 5 registers the token successfully it shows up as being registered to the correct channel. However when I send a message (using the PubNub dev console) both the S5 and the iPhone get the notification, however the Nexus 5 doesn't. When I go back to check if it's still registered to a channel, the channel has disappeared.
So basically it seems that whenever I send a message on the channel, the nexus 5 is just removed before it even gets the message. While the other devices stay connected and get the message.
(BTW this also happened when the S5 was not subscribed for that channel)