On some devices when the keyboard pops up for a password field, numbers flash briefly at the top of the keyboard then vanish, when they vanish they leave the screen unpainted with parts of the screen before it was resized showing.
It seems you need to click on a normal text field then click on a password one on some phones numbers will appear and vanish showing the issue, sometimes you need to go back to the normal textfield to get the numbers to disappear to show it.
Shall I file an issue Shai or is this known ?