Works everywhere but iOS10.3

Hi,

I've got push notifications working on iOS11 and all android, but for some reason it's not working on iOS10.3.

Everything is configured using FCM, react-native-fcm and a .p8 certificate.

On iOS10.3, I'm simply not getting APNs notifications. It asks for the permission, I see the FCM token, but the APN part is just not triggered, neither on the foreground or background.

However, on iOS11, everything works as expected.. I can send a push notif. from the server or using the FCM UI.

Is iOS11 using a different method for APN messages which could explain this issue?

Thanks