No one ever receives my Game Center invites

I send Game Center invites but no one ever receives them. Friends also try to send me invites, but I've only gotten three of them. For some reason, most requests never make it to me and none of the ones I send are ever received. I'm using iOS 8.1.2 on an iPhone 6 Plus. I have gone through all of my settings and made sure I have invites allowed and my profile is public. I've made sure restrictions are turned off and notifications are turned on. I don't know what else to do. What could possibly be causing this problem?