Why does my note 4 keep restarting and the asking me for my backup password?

[AC Question]

It is not a total restart. It restarts from the Sprint screen. It forces me to enter my backup password and does not let me use my thumb print. This has been happening at least 5 times ever morning I am streaming IHeart Radio. The problem started immediately after the Marshmallow upgrade.

 

[sydneycooper1979]

It's generally a good idea to do a factory reset when you have a major software update. Sometimes things get hung up between the old software and the new one.