When I say turn the phone off, I don’t mean just press the button so the screen goes off, I mean actually turn the phone off. It’s probably worth trying a forced restart. You don’t lose any data or settings or anything by doing that and if only takes about one minute to do.
From Google for an iPhone 11 you do it like this.
Force restart iPhone X, iPhone XS, iPhone XR, iPhone 11, or iPhone 12. Press and quickly release the volume up button , press and quickly release the volume down button, then press and hold the side button. When the Apple logo appears, release the button.
Regarding unpairing and repairing your hearing aids, I don’t think that it would help at all but anyway it’s nothing to be frightened of doing.