Touch ID no longer responding consistently

I have a 2 year old MacBook Air (Retina, 13-inch, 2020) running macOS Monterey 12.2.1. About 10 days ago, my touch ID became unreliable when using Safari. Safari is the only place I use it.

I thought that perhaps the saved fingerprint file had become corrupted, so I deleted it and created a new one. Seemed to work okay for a couple of days, then the same behavior re-appeared.

I've cleaned the Touch Pad, and my finger doesn't appear to be marred in any way: no scratches, grease, etc. Besides ... sometimes it works. I haven't been able to discern any patterns in when it works and when it doesn't.

Any ideas?