On my site, there are two fields on the sign in page: one for email, one for password. If I have already signed up, log out, and go back to sign in, Chrome autofills the username into the email text box instead of the email address.
<div class="inputs">
<%= devise_error_messages! %>
<label id="maincontent" class="control-label sr-hidden" for="email">Email Address</label>
<input id="email-input" name="email" type="email" required='true' autocompletetype='email' autofocus='true' placeholder='Enter your email address...'/>
<label class="control-label sr-hidden" for="password">Password</label>
<%= f.password_field :password, :required => false, :placeholder => "Enter your password...", :id => "password" %>
</div>
In addition, if I delete the password field altogether, no autofill happens at all in the email field and it is left blank. If you click in the field, the drop down autocomplete menu pops up, however.
EDIT[SOLVED]: I switched the name and email fields on the sign up page
chrome assigns a ‘default login credential’ status to whatever field is directly above the password on the sign up page
it recalls that credential automatically for autofill in the field above a password field on the sign in page
it requires one to go to settings>passwords and forms > manage passwords and deleting the erroneous default, and then signing in/up again on the corrected forms