Fields in columns not displaying side by side

I’m trying to make a mailpoet sign up form. I have first name and last name boxes in a two column block, and in the mail poet preview they display correctly, but on my live page, they display vertically above and below each other, not side to side. Plus, which ever one is second is slightly indented on the live page.

I’ve tried every variation I can think of, redoing the columns, redoing the entire form, switching the position of which one is left and right, resizing the form, resizing columns, making it the full width of the page, but nothing I do makes any difference.

The MP form is about halfway down the page, under behavior tracking journal. I have an elementor signup form that displays correctly at the bottom of the page for comparison. This is what I want it to look like. The only reason I’m trying to use the MP sign up form is that I want people to select which list they sign up for.

The page I need help with: [log in to see the link]