"Double Tap to unlock" problem

[Sci10213]

Hi

 

I have this problem with Samsung Ace 4 new model... no idea how it occured but now everytime I make outbound call, the big padlock logo appeared with message: Double Tap to unlock ...

 

This keeps on happening. I tried to google for answers and there are a lot of suggestions BUT none works.

- this is not Screen Lock settings issue

- this is not TalkBack settings issue

 

BTW, this problem can occur in many Samsung smartphones (as from the info gathered online)

 

I have emailed to Samsung to seek help but no reply from them yet.

 

My last option is to do a factory reset but before doing so, I like to know if anyone faced such problems? Please share how to remove this padlock setting forever...