Note 4. Scanner not working. Please help.

[AC Question]

Hi, my note 4 fingerprint scanner has stopped working, so I've been using the backup password to log in. Fine, however when I go into my settings and try to solve the problems I get asked for my backup password, I type in the same password (the EXACT same, believe me I've checked several times) and I'm told it's not the correct password????

So I'm pretty stumped. Anyone came across this problem before. The fingerprint scanner issue is one thing but the backup password problem is baffling.

Cheers.