Messages on my iPhone 15 Pro disappear

I’ll see the notification for a second , and then it’ll disappear from the Notification Center, and I haven’t opened it or opened the app , nor the message. It’s annoying when people text me and I can’t see it

my messages are disappearing like i read them, but i didnt open the messages app. ill recieve a notification and it will just disappear , but i didnt read them.

[Re-Titled by Moderator]