I have an iPhone 6S (with iOS 11) which is working fine except for the fact that I no longer receive any push notifications whenever I receive a new text message - no sound either. All I see is a badge on the icon. I can't understand why, especially since all push notifications options for the Messages app are on in Settings (e.g. "Show on Lock Screen", "Show as Banners").
Push notifications for other apps work fine. Also, I don't have Do Not Disturb mode on, and the phone is not on silent.