So it appears to me that a serious issue is at play here, maybe it's just my tablet somehow or a wider issue at large.
Hopefully if enough people read this and test this on their own S9 Ultras (or any tablet with underscreen fingerprint scanners) we can determine if it's a wider issue.
I'll explain what happened. I use my Tab S9 Ultra both for work and a my main at home 'computer'. I was away from the tablet at the other side of the room and my coworker just out of curiosity put her thumb on the fingerprint sensor that appears when on the lock screen and on the very first attempt she gained access to my tablet. We joke around a lot at work so I took her claim as a joke but she sounded convincingly serious so I went back to check and it was on and logged in. But as she is an Apple user who is not very tech savvy (her admission as well as mine) I initially though she must have accidentally swiped the screen to access it using the sensor or maybe it was already unlocked with Extend Unlock (I was 99.99% sure at the time that it wasn't the case but im now 100%).
So I put it back to the lock screen then asked her to do it again to prove it. Either on the first or second attempt I cant remember, she logged right in. I could not believe it. I regularly leave the tablet unattended at work and this entire time someone could have easily been accessing my personal files and photos. The end..... just kidding.
I shouted over another colleague of mine to try. Press, press, press then boom it let them log in too. In that moment I was considering yeeting the stupid thing out the back door downwind during a storm and calling it a day. But the humiliation wasn't over as another colleague then managed to gain access with a slight bit more difficulty than the first 2 and 1 further colleague being unable to before triggering a too many failed attempts prompt. Everyone used the thumb on their right hand which is the fingerprint I use to unlock it most of the time. I filmed 2 or 3 of my colleagues unlocking the tablet, I then did an admittedly poor job filming my colleague unlock it before I then relock it, unlock it with my print, going into settings, getting lost, accidentally opening an app but eventually reaching biometrics under security to show the check my fingerprints part where my thumb shows up as fingerprint 1 and my left ring finger? showing up as fingerprint 2 and immediately after the colleague who initially unlocked it checks theirs and it comes up as fingerprint 1.
Unfortunately though having looked over the videos the swearing is pretty bad (mainly from me) and I'm not wanting to post videos here that include peoples faces or voices who didn't explicitly agree to be shown on a public forum.
However, I think parts of the videos with the audio removed and no faces showing could be posted whilst still showing some sort of proof that the fingerprint sensor is not fit for purpose. No promises though if it's time consuming I likely will not knowing myself but I'll try
But regardless, an absolute disgrace. A £1449 tablet (£1778 with keyboard case) that can't properly use biometrics to lock safely whatsoever. One with a notch that can't sufficiently do face unlock in a secure way even though it has two cameras and surely could scan your face using both simultaneously for something that's better than the current implementation. For the price they should have put an ultrasonic scanner in it. I'm now beginning to think the fingerprint sensor icon of a fingerprint is the actual resolution that the actual fingerprint sensor is capable of capturing.
I'll get in touch with Samsung tomorrow with the info I have and I'll report back at some point.
