I have had 4 sensors fail the same way.
The latest response I got from Support was to try a Panasonic or Duracell CR2450 battery as others have minor dimensional differences that don’t make contact to both + and - terminals. I have not tried this yet.
https://community.smartthings.com/t/how-reliable-are-your-smartthings-motion-sensors/71735?u=keo