Open Radar

 
Summary:
Note: use device with TouchID and a complex passcode to reproduce!
The problem arises when the user fails TouchID and then taps on "Enter Passcode" to authenticate via device passcode instead. I noticed that the screen that gets presented is plain white, and the passcode text-box does not show a value for the last character entered until it is masked (after a bout a one or two second delay), creating a strange user experience.

Steps to Reproduce:
1. use a device with TouchID and complex device passcode
2. authenticate in an app that utilizes TouchID with Keychain
3. fail TouchID to make the "Enter Passcode" button appear
4. tap on "Enter Passcode"

Expected Results:
I would expect to see immediate feedback when characters are typed.  It should display the character typed last for a couple of seconds (whatever the standard delay is) and then mask that character when the next one is typed, or the delay times out.  I also think that the screen presented lacks refinement, but that is just my personal opinion when I compare it to the native passcode screen.

Actual Results:
I don't see immediate feedback when a character is types.  For example, on the very first character, the text-box is blank until the delay times out and the masked character appears.