This morning I experienced the weirdest thing by my iPhone 6S requiring me to enter my passcode rather than allowing me to use my finger as Touch ID.
My phone was locked probably for like 4 hours while charging overnight and as far as my knowledge my phone did not restart during this time since my Stack Exchange app was left open and upon opening it the same content were still there.
I didn't attempt even once to use my Touch ID; if I would've had a faulty Touch ID sensor then I should've seen such similar behavior either prior to this morning or at least afterwards (I'm already on my phone for the past 3 hours plus).
I didn't register or delete any fingerprints for months.
And finally, I don't have any restrictions setup to require the input of my passcode under Settings > General > Restrictions.
I'm running on iOS Version 10.0 beta 3 (14A5309d)
Anyone out there that has also experienced such similar behavior or with any suggestion on what might've caused it?