Passwords Suggestions

So I have a login form working great, typing in the username and password works fine and I can successfully login.

However, if I fill in the password from Keychain on iOS by pressing the “Passwords” link on the keyboard searching for the password, selecting and the form gets filled in upon clicking submit for the login form it states unrecognised username/password. However if I copy the password instead of allowing iOS to refill then it works.

Also, is there a way to hint to keychain to prefill the password/login info from a particular website. My login form logs my users in by checking with a pre existing open website so most users will have saved info in keychain.