Spirit Update Styling Error with Form Display

I have a form integrated on my website which runs with the Upfront -> Spirit theme.
When I view the form in the 2015/2016 wordpress themes, the radio buttons for the different options are displayed. When I view the form on the live page with the Spirit theme, I can't see or select the radio buttons.

This is a really weird conflict and it's preventing users from becoming members with my business. Please help!