This may not be isolated to just Equivalent Domains, but it is where I've run into the problem most recently. The password verification dialog pop-up through the website (I'm using Chrome) does not handle the Enter/Return key appropriately. It is universally standard that hitting Enter/Return after the password would start the submission/login process. This LastPass dialog, however, not only does not respond according, but also inserts a hidden character into the password field that then causes the password check to fail after you give up and hit the GUI button anyway.
Trying to determine why a password fails with redacted fields is already pain enough without this hidden complication. It took me several attempts to realize my password was *not* wrong, but I just had an embedded behavior to immediately hit "Enter" after my password.
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