checkout form does not appear for guests

Hi buddys,

We have a web page to sell our product, landing page -> checkout page, it was working like a charm until about a month ago, but suddenly the checkout fields stopped showing up to guests. I tried several things to fix, like disabling all plug-ins, changing the theme, etc. But without success.

Note: Our product is not recurring, we mark “Allow customers to place orders without an account”.

Has anyone had a similar problem, or have any ideas about it?

Thank you guys!

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