Version: 51.0.2704.63 (64-bit)
OS: GNU/Linux (likely platform-independent)

What steps will reproduce the problem?
(1) Visit https://paket.de. Ensure to have a credential saved on that site.
(2) Get the credential filled in the login form (top right).
(3) Submit the form via the Login button.

What is the expected output?
The site should display a captcha after step (2).

What do you see instead?
The captcha is not displayed, and the submit does not succeed. Unless the user triggers some kind of events in the password field, the captcha is never displayed, which is confusing.


Notes:
(A) To try this out without the need to register a paket.de account, try enabling the chrome://flags/#enable-password-force-saving flag and saving the password manually in the login form.

(B) I'm Cc-ing sebsg@ and dvadym@, because we had a discussion about firing events on filling password fields last week. This might be the issue where using SetAutofillValue for password autofill would help.