failing to secure lock screen

[AC Question]

I was using the finger print option on my S5 for some time and changed to a password. However, when i lock my screen it reverts to the swipe option. Under my settings it shows that it is secured with a password. And when i try to enter the password it is saying the password is incorrect but i am 300% sure i am entering the correct password. I can't use options inder security as the password is failing and some options are grayed out. Please assit me guys as i need to secure my phone. I look forward to favourable responses. Thank you all.