My Face ID on the X did that. It was in my pocket during a torrential downpour. It got wet, and had to be replaced. Fortunately, it was covered under AppleCare.

Since you are running Beta software, you need to ask the Apple Beta Support Team.

iPhone is definitely better for older people. I helped my 82 year old father yesterday with his Android, and it is horrible. He also uses it to play music. He bought a brand new 2024 truck. The Android Auto is horrible. He must still use his phone screen to play music, as the app will not display his music library or playlists on the huge infotainment screen in the truck.

So, not only would an iPhone be better for his hearing and sight, it will also be much, much easier for him to use for every day usage.