Embedded HTML creating issues with app users

Our app regularly hosts contests, embedding from Second Street.
We recently had to layoff the person that did all the contesting. While I have familiarity with UI, this is my first time using Plasmic. I am getting through it, and I walked through the previous contests to make sure I didnt miss a step. From what I can tell, I have done exactly the same thing - from creating Second Street embed HTML, to mirroring the Plasmic side of things.

The issue comes from the verification screen, on the below contest page. The verification just spins, and never progresses. However, when I try to enter via the link through a browser, it works just fine.

Relevant links:

Previous project: Plasmic