Galaxy S6 Tab LTE refuses to register my fingerprint

[WobSleptHere]

I purchased my new Galaxy S6 Tab LTE recently and have tried numerous times to get it to register my fingerprint. I go through the motions where it tells me:
Start scanning with the centre of your fingertip
I press as instructed and it tells me 12%. I lift off and press again and it goes to 18% and so on moving my finger around as instructed. Sometimes it gets to 20% and gives up, and sometimes it even gets to around 60% but still gives up saying:
Couldn't register your fingerprint

I've tried and tried again dozens of times, but it will never finish and register the fingerprint. Interestingly I also have a Galaxy A51 phone and have experienced no serious problem registering, not just one, but several of my fingerprints. Sometimes it took a couple of goes but I always got there without significant problems.

Have others experienced similar problems with the S6 or can anyone suggest a solution for solving my problem?

[Ksmy89]

Have you got a screen protector installed on the tablet?

[WobSleptHere]

@Ksmy89 wrote:
Have you got a screen protector installed on the tablet?

---

No, the screen is exactly as delivered new. I have stuck nothing on it but I do have the S6 mounted in an Infiland Case designed specifically for this tablet but that doesn't cover the screen in any way.  I don't normally use the S-pen but just my finger for operating the tablet. Just to be sure I have thoroughly wiped it with screen cleaner and it makes no difference.

In the past 10 minutes I have again made about 6 attempts. At each attempt, it got only as far as 20% before quitting.

Given that today I added 2 separate fingerprints to my Galaxy A21 which took a couple of minutes or so. Then the same 2 fingerprints to a third party device which also completed in a few minutes. So there is clearly nothing wrong with my fingers either!

[WobSleptHere]

Now, several months later I still cannot set up my fingerprint on this tablet. As stated before I do not have a screen protector or anything else on top of my screen. The screen looks new and totally undamaged just like the day I purchased the tablet. The tablet is fully up to date on software and everything else works fine. I have wiped it with screen cleaner, I've tried using different fingers all to no avail. I've had no trouble at all setting my fingerprints on other devices (including Galaxy A51) where it took me a just seconds to generate each fingerprint.

Is there some setting I have to adjust in Samsung Knox to persuade it to set up my fingerprint?