Tappy Chicken's Game Center doesn't update?

Hey, I’ve been playing Tappy Chicken on my iPhone while digging into its blueprint and found that it doesn’t update the achievements. I somehow have some data in my game center (must’ve been playing before) so I’m wondering if the data is just really slow or whether the latest version of Tappy doesn’t store it properly?

My main reason for checking it is to see if using Game Center with UE will show any message in-game when you complete an achievement or not? Or do I have to code that myself?