Samsung Galaxy Tab — Marshmellow has screwed up my S2 9.7" security feature.

Can anyone help me with a technical hitch?

I bought a Samsung Galaxy Tab S2 9.7" as a belated Christmas present to myself earlier this year and it's been going along swimmingly since then, other than the fact that the fingerprint security feature is a real pain in the butt. Half the time it won't read my print, meaning I have to go the backup password, but other than that I love it - my first tablet.

Last night it asked me if I wanted to update to the latest version of android, and I automatically gave it permission to do so. Well, worst thing I could have done - I currently can't get in to the damn thing because of the security feature. Normally with the tablet it will let you try to enter your fingerprint on the reader 3 - 4 times, and if it doesn't work it pops up a graphic keyboard to enter the backup password. Instead, what it's now doing is enforcing a delay before I can try and access the device again. It doesn't even try to accept my fingerprint, just as soon as I put my finger on the reader it automatically doubles the wait time - I'm currently out to an hour! If I keep going it will stretch out to days!

I took it along to the store I bought it from (Best Buy), thinking the rep might know how to get around it, but he just vaguely suggested it had nothing to do with the hardware and that I'd have to access my google account to try and sort out the security. I went there but couldn't find anything even remotely connected to the situation. The only thing I could find was a reference to my tablet, which said I hadn't tried connecting for 17 hours.

Anyone got a suggestion, other than throwing the tablet into the pool? If I can get in I'm going to disable the fingerprint feature - I've only belatedly discovered that this can be done.