If your phone in-screen fingerprint not working or, not detected could be the result of ***dirty or wet sensorsurface***. or, there's an error with the fingerprint software.
If the app and cache storage memory of your phone has been exhausted, it may also not detect your fingerprint. To fix this issue, find out what is taking up all the space in your storage and delete them. In addition, you can select the ‘Clear cache’ button and delete cached items. This will free up space and make it possible for you to use the fingerprint option.