Tab Index on Password Field

Hi,

I'm seeing a problem when tabbing through a form, the password (with confirm) field gets skipped in the tab order. I've set this forms tab index to be very high as to not conflict:

[gravityform id="2" name="User Registration" title="false" description="false" ajax="true" tabindex="400"]

Here's a link to the form:

https://www.askdrterry.com/ask-a-question/

Try tabbing through the user registration form and you'll see when you get to the password fields it gets skipped. Please advise.

Thanks!