Payment options spinning, not loading

Something happened with my clients checkout page sometime in the last couple of months from what they can recall and is experiencing it on all of their Infusionsoft checkout pages. Here’s a URL as an example: 100% Secure Checkout - Evan Marc Katz

When a customer fills out their address, the Ajax calls occurs and multiple datasets are returned however the payment plan options never load. I took a look at the json data returned and there is an payplanID attribute which is null. None of the renderFormElement calls are related to the payment plan information either - not sure if it’s related.

Any thoughts on what could be causing this? I’m not very familiar infusionsoft so am flying a bit blind as to what should be happening.