how to disable number highlighting when typing password to unlock screen
typed numbers shouldn't be highlighted, how can i type the password in the bus or metro? it is very easy to spot the password...
Every device does this as far as I know, iPhones and Android. If people are close enough to see what buttons you're pressing, not having them highlighted won't change anything. If you're worried about strangers seeing your pin try using a longer one, no one will memorise it on one glance.
Or type faster.
If you really don't want the highlights to appear, then vote or suggest that feature in the Windows Feedback app (if you're using Windows 10 Mobile).