Strange auto fill failure

[cglenn7777]

I wanted to name the moon! That's all. I went to this site (http://namethemoon.world/#/Facts-0), clicked on the big blue 'name the moon,' was sent to a form, clicked the autofill icon, all but the state dropdown list were accurately filled in (Chrome seems to have figured this out recently). I selected state, then submitted, only to be rejected, with all the auto-filled fields highlighted.

I had to delete and keyboard type the exact same characters for the form to submit. How can a form see auto-filled fields as empty?