Randomly muted text thread with fiancé on iPhone

My conversation thread with my fiancé always gets randomly muted. Sometimes it takes me a while to notice, I usually notice when I realize his texts aren’t coming through to my watch. I have to go into the text thread and turn off the “hide alerts” button that always randomly re-enables itself. It’s honestly very frustrating and it’s only with his messages. My iPhone is currently on its newest update. Nothing is my notification settings would enable this “feature” either.

[Re-Titled by Moderator]

Original Title: “Hide Alerts” being reenabled.