Hi, so we developed a redesign and upgrade of our company's site over the past few months and everything worked fine.

We swapped the servers for our domain, and now all of the sudden forms that post are not working in IE9 and below. Oddly, after putting the site live, we created a backup which runs on another server and all of the forms work on that site just fine.

At first, I thought it was just the registration form and after some Googling I found that you can add a placeholder attribute to all of the fields and it will work fine, which it did. However, our checkout process has a section with two radio buttons and I can't do the same for those inputs so nobody on IE9 or below is able to checkout.

I can't find any solutions, but it's a pretty major issue. Does anybody have ideas on how to fix this?

I've checked the output from the form IMMEDIATELY after submitting, and it shows the form fields as having no data so I know it's not any javascript or anything altering the info. This has been driving me insane, I'm praying somebody can help me figure this out =(