How many placeholder characters are required for the password entry box?

Question

Unicode

One of the options for hiding the password entered by the user is to replace the entered character with one specific one, for example, "*".
The password can be from any characters, including compound ones (for example, "й").
Tested in chrome - two replacement characters per input. In the "run as a different user" dialog in Windows - also.
It turns out that they have a problem in the implementation?