Just updated to iOS 17.1.1 on iPhone 13 Pro, and noticed this. By “hearing devices screen” I mean the screen reached by triple-click if enabled, or from the Hearing icon in the Control Center. It’s nominally the same screen whichever way you reach it.
If you reach the screen via triple-click, the Live Listen button always shows the “off” indication, even if it’s on. You can turn Live Listen on from this screen, but you can’t turn it off. If you reach the screen via Control Center then the Live Listen button works properly.